Cost guide: Drainage & services

 

From drainage and septic tanks to mains gas connections, Tim Doherty looks at the costs involved with getting your utilities in order

Before you start a self build, you need to be sure about the location of your services going in, and your drains coming out. These will most typically need to run over your foundation and through the blockwork.

What are drainage products?
Years ago you could often find combined systems, but today drains are very firmly divided into two categories of foul and surface water.
The foul drainage system will take everything away from sinks, showers, baths and WCs and will need to discharge directly into the council’s neighbouring main. Where this is simply not an option, you’ll need to have your own discrete septic tank, treatment plant or cess pool.
The drains themselves can be installed in plastic or clay, with the former being a lighter and more workable choice. Equally your manholes and inspection chambers can be built of brick or proprietary plastic – the latter is significantly cheaper in terms of its overall installation cost.
There are good discounts to be had on drainage products and your local merchants will happily price the overall supply based upon a linear length of the runs, the number of chambers and covers.
As a rule of thumb, the supply only of a plastic inspection chamber will cost about £160. This should include the base, shaft(s) and cover. Plastic pipe is about £4 per m, while clay will be twice the price. Plastic pipe also comes in 6m lengths (as opposed to 1m for clay).

How to install a drainage system
If you are connecting to the mains in the road then you’ll take your drainage installation only as far as your plot boundary. You’ll have to have a quote directly from your local drainage provider for the work necessary to excavate across the pavement and into the road for the final connection.
Work on public highways is strictly controlled and only approved contractors are licensed to undertake this work – it is therefore expensive.
Your application will involve clarification of the main sewer’s invert level so that the fall on your site drainage installation is compliant.
Where your site is lower than the main sewer, one option may be to take your drainage to a central domestic pumping station to enable you to pump to higher ground. Here, the eventual outflow will have a compliant fall into the mains but, needless to say, this will add more cost.
A typical domestic sized pumping station together with an alarm could be in the region of £1,800 for its supply and probably another £1,000 for its complete installation. This will also require an electrical feed.

What are septic tanks and treatment plants?
Where a mains discharge is not possible you can consider septic tanks and small treatment plants. This is on the proviso that your soil conditions are porous and, in the case of septic tanks, are far enough away from any natural water courses.
An installed septic tank could cost you £1,500 to £2,000 (£600 for the unit) and a proprietary treatment plant, which needs an electrical supply and has moving parts, will be closer to £4,500 (£3,000 for just the unit).
Both require emptying usually twice a year at about £100 a time. Annual servicing of a treatment plant could be £250 plus parts but, believe me, this is money well spent.
Where there is inadequate soil porosity you’ll need a cess pit, which is bigger by definition and more expensive than a septic tank. It will always need more emptying by virtue of retaining everything that flows into it.
The Environment Agency will need to approve your porosity test before granting approval for a septic tank or treatment plant at the Building Regulations stage.
For surface water discharge the most common solution will be soakaways, with numerous irrigation options dependent upon your soil conditions. Surface water drainage will use the same type of pipe and inspection chambers as the foul.
A typical detached house could easily use 100m of drain pipe and four or five inspection chambers dependent upon your layout.

Services for self build projects
Service supplies into your property will include mains gas (unless you are using a containerised fuel), water, electricity, telephone and quite possibly cable.
Water should sit at a trench depth of 750mm, gas at 600mm, electric at 450mm and phone/cable should be OK at 350mm.
Gas and water supplies are not normally ducted, electric can be through choice, but phone and cable will always need to be ducted to protect the cable’s integrity.
Depending on the timetable for your service connections, you can build your trench work excavation plan around the mains gas supply.
Do this by excavating and laying your water pipe, organising the regulated gas installation and then ducting for the electric, telephone and cable.
The golden rule with services is to get your applications in as early as possible, secure a formal quotation from each utility company, pay their infrastructure charges quickly and you will then be in the queue for the work to be scheduled.
Only at this point can you begin to influence the timetable around your other works on site.




source http://www.self-build.co.uk/cost-guide-drainage-services

Project Planner: Conservation Areas explained Experienced renovator Michael Holmes advises on areas of special architectural interest.

Project Planner: Conservation Areas explained

Experienced renovator Michael Holmes advises on areas of special architectural interest.

By Michael Holmes



 


Experienced renovator Michael Holmes advises on areas of special architectural interest in the second part of a new series. 
The owners of this fisherman’s cottage in Padstow, Cornwall, had to change their plans for a roof terrace after planning permission was refused due to the property being in a Conservation Area.

What is a Conservation Area?

First established in 1967 by the Civic Amenities Act, Conservation Areas recognise and protect parts of the country considered to be of rich architectural heritage, landscape or historical value. They use the powers of the law to prevent inappropriate development, demolition and advertising.
There are now more than 9,300 Conservation Areas in England, around 600 in Scotland, 500 in Wales and 60 in Northern Ireland, together forming an important part of the nation’s heritage policy.
The legislation recognises that it’s not just the buildings that define an area’s character, but the sum of the elements that contribute to a sense of place, including layout, historic street plans, boundaries and thoroughfares, vistas along streets and between buildings, open spaces, the use of traditional materials and details, trees and landscaping, so all these are also protected

Do I live in a Conversation Area?

Your local planning authority (LPA) will be able to advise whether you live in a Conservation Area, as will a quick search of the LPA website. Go to Planningportal.gov.uk/inyourarea to find further details. You will also be able to find the Conservation Area statement, which documents the history of the area, important characteristics, planning policy, and details of which restrictions to permitted development (PD) rights are in place and apply to your property.
Living in a Conservation Area has its advantages: properties are often worth more because of the character of the area and according to studies by the London School of Economics, tend to increase in value faster than other areas because they are more desirable places to live.
Planning controls ensure that what is most valuable about the character of the Conservation Area will be preserved, including trees and open spaces, but the quid pro quo is that there are restrictions on the alterations and improvements that you are able to undertake to your own property.

Are my permitted development rights affected?

If you live in a Conservation Area or other ‘designated area’ such as a National Park, an Area of Outstanding Natural Beauty or the Norfolk or Suffolk Broads, you will need to apply for planning permission for many alterations normally classed as permitted development in other areas, including to the roof, change of roof covering, adding timber, render or stone cladding, side extensions, rear extensions of more than one storey and demolition.
Many properties within Conservation Areas are also subject to further restrictions on PD rights under Article 4 Directions. This can include changing doors and windows, adding rooflights, painting the external walls and external joinery, adding satellite dishes or solar panels and any other alterations that could change the appearance of the area. If an application for planning permission is required because of an Article 4 Direction, there is no fee for the planning application involved.
Planning permission will not normally be needed for straightforward repair work, and if you are carrying out work to the interior of a building that does not affect the external appearance. It’s important to remember that flats do not have PD rights, and so planning permission will always be needed for all external alterations that will alter the building’s appearance.

Can I still improve my home?

Designation as a Conservation Area does not place a ban upon all new development within its boundaries. You may still carry out the following using PD rights, provided that an Article 4 Direction is not in place:

• undertake a loft conversion with rooflights (but not dormer windows);
• add a single-storey rear extension across the width of the original rear wall and projecting by four metres, as long as it is no more than four metres high (three metres with a flat roof) and with eaves no higher than 2.5 metres within two metres of the boundary;
• add a porch measuring up to three square metres if it is no more than three metres in height and less than two metres from the highway;
• paint the house and external joinery;
• add solar panels, provided that they do not stand out from the plane of the roof by more than 150mm; n convert a garage and add new window openings; n construct outbuildings covering up to half of the original garden, where they are behind the house and no more than four metres in height (three metres with a flat roof) and with eaves no higher than 2.5 metres within two metres of the boundary; and
• add gates, fences and garden walls up to 1.8 metres in height on the boundary, and 60cm on the boundary with the highway.

It is always worth checking with your LPA whether planning permission is required before undertaking any work. For certainty you can apply for a Certificate of Lawful Development, the current fee being £86 in England (£172 for an existing use or development) and £165 in Wales. Where permission is required it will be subject to closer scrutiny than in other areas, and so particular attention must be given to the height and scale of proposals, the form and layout including the footprint, setting and relationship with other surrounding buildings (the streetscape) the materials and details used, and the landscaping scheme.
Applications are only likely to be approved if it can be demonstrated that the Conservation Area’s character or appearance is not harmed, or that it can be positively enhanced through good quality design. Extensions will usually be considered appropriate if they use traditional form, are subservient to the existing building and use traditional local materials and detailing. High-quality contemporary design can also be acceptable, especially where it can be shown to integrate traditional materials and craftsmanship, and architectural details and features with a local connection.

Who decides whether to approve my proposals?

As well as being reviewed by LPA planning officers, an application affecting a Conservation Area will have to be approved by the LPA’s conservation officer, who will determine what is acceptable in relation to its Conservation Area policy and national planning policy.
The degree of subjectivity is far greater than in other areas of planning and so it can be useful to speak to builders and designers who have worked in the area and have an understanding of the approach taken. Larger and more significant applications, especially those in the setting of a listed building or other heritage assets will be sent for comment from English Heritage, or the equivalent (Cadw in Wales, Historic Scotland and Built Heritage in Northern Ireland).
In England and Wales, parish councils will also be consulted, as well as Conservation Area Advisory Committees

Do I need Conservation Area consent?

The total demolition of a building or structure in a Conservation Area (with the exception of buildings under 115 square metres, or gates walls or fences under two metres in height or one metre next to a highway) currently requires consent in Wales, Scotland and Northern Ireland, including the demolition of a building leaving only the facade.
Conservation Area consent was abolished in England on 1 October 2013 and demolition is now dealt with in the mainstream planning system. Wales, Scotland and Northern Ireland are currently reviewing heritage policy and are likely to follow suit. Demolition without consent is unlawful and the owner may be required to reinstate the building, with there being no time limit on enforcement action.

Are trees protected?

Trees play an important role in the character of many designated areas and consequently almost all trees other than saplings are protected within a Conservation Area.
Undertaking any works to a tree with a trunk diameter greater than 75mm at 1.5 metres above ground level requires consent, and the LPA must be notified six weeks in advance in order for a decision on a Tree Preservation Order to be made.
Summary conviction for removing or damaging a tree without consent is a criminal offence and carries a fine of up to £30,000, with more serious offences dealt with by the Crown Courts, carrying an unlimited fine. It will also be the landowner’s duty to plan replacement trees of appropriate size and species in the same location as soon as possible What if my proposal is refused? As with any planning application, if your proposals are refused permission or the LPA fails to determine the application within eight weeks of registering it, you can choose to make an appeal to the Planning Inspectorate.

What about listed building consent?

Many buildings in a Conservation Area are also individually or group listed, adding a further layer of protection. If your property is listed you will also need listed building consent for any ‘material alterations’, both internally and externally, whether or not they require planning permission


source;
https://www.realhomesmagazine.co.uk/advice/project-planner-conservation-areas-explained/

Ultimate guide to extending your home

From costing and designing extensions to permitted development and building regulations, find out everything you need to know here.

 

 

 

How much will an extension cost?

You’ll need to allow around £1,500 per square metre for the building work — and, for higher specification finishes, up to £3,000 per square metre. If you’re adding bi-fold doors, allow £1,400 to £1,800 per metre for these. Bear in mind that small extensions (under 15–20 square metres) have higher costs per square metre, and that clay, peat, lots of nearby trees, or sloping ground will increase foundation costs.
‘As a very rough rule of thumb, costs should be split into 50 per cent for construction and 50 per cent for the interior,’ says Hugo Tugman, founder of Architect Your Home and Interior Your Home. ‘If you do not want to compromise on the size of what you are building, you may be able to make considerable savings on interior finishes.

This Scandinavian style kitchen extension in London cost less than £70k,

For example, tiles can range from £15 to £150 per square metre; timber flooring from £30 to £300. The more expensive options are generally much better quality and more beautiful, but therein lies the compromise in meeting your budget.
It is important that you get quotes from at least four builders. It is almost certain that each of the builders will provide different costs for exactly the same work using the same materials. If you only approach one or two builders, you run the risk of only obtaining high quotes, rather than getting an idea of an average.

Click here to get a comprehensive extension cost calculation using our free extension cost calculator

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Planning permission and permitted development for extensions

How to extend without planning permission

‘Homeowners are sometimes surprised at how much can be built on to a house under permitted development rights,’ says Alan Cronshaw of Acronym Architecture & Design. Even in Conservation Areas you can build rear extensions as long as they meet the size criteria and are in matching materials.
If you are planning to build an extension under permitted development rights, study the criteria carefully and apply for a certificate of lawful development from your local authority. This only costs £86, and you will then have the paperwork in place to prove that your extension did not require planning permission.

This industrial-style glazed kitchen extension took two years to get planning permission,

When you will need planning permission for your extension

The cost of a planning application is £172, an expenditure that you don’t want to have to make several times. Make sure you have gone through your plans thoroughly with an architect or builder that is familiar with the local planning council and their preferences.

When building a more ambitious extension you will need planning permission if:

• Your extension covers half the area of land surrounding your home
• If you are extending towards a road
• You are increasing the overall height of the building
• You are extending more than six meters from the rear of a semi-detached house*
• You are extending more than eight meters from the rear of a detached house*
• Your single storey extension is taller than four meters
• Your single storey extension is to the side of the property and more than half the width of your house
• You are using materials that differ from the original style of the house
• You plan on building a balcony or raised veranda

For more detail on when you will need planning permission, visit the Planning Portal

*For a period of six years, between 30 May 2013 and 30 May 2019 – householders will be able to build larger single-storey rear extensions under permitted development.

What to do if a planning application is rejected

‘First, it’s important to try to understand exactly why the application was rejected,’ says Hugo Tugman. ‘The proposals may be largely acceptable, but simply contain a detail that the local authority can’t approve, in which case resubmitting a new application that has been amended accordingly should be enough to get the permission that you require.
‘It may, however, be that what you are proposing is fundamentally outside the planning policy or guidance the planners are working with. If that is the case, you really need to understand what these policies are and redesign so that your scheme falls within these parameters.
‘The third possibility is that you feel your scheme was within the policy guidance, but the planning department has made an unreasonable interpretation of the rules and refused it. In this final case it may well be worth going to an appeal, where an inspector (not local authority) makes an independent assessment of whether policy has been applied correctly and reasonably.’

Changing your extension design

Changing your extension design after your planning application has been accepted will require a retrospective amendment, or a new application all together. The key to avoiding this situation is to study your plans in detail and have a physical or digital model created to help with visualization.

Annabelle and Jack Diggle had to navigate a particularly strict planning office to get this traditional, pitched roof extension,

‘Occasionally, situational developments may mean that changes are unavoidable and retrospective amendments sound like a good idea. However, in recent years planning departments have been less ready to go down this path.’ says Hugo.
‘If the changes are very slight, it is indeed possible to apply for a “non-material amendment”, but changes that may affect anything significant, such as the overall height or positioning of upstairs windows, would be “material”, and the planners would have to advertise all over again, so they generally push you down the route of a new application.’

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Single storey extensions and two storey extensions

‘You are far more likely to get planning permission for a one-storey extension than one with two floors,’ says Hugo. ‘If you can get two storeys approved, there are definite cost benefits, because you will be getting twice as many square metres of additional space in your home for considerably less than double the cost of a single storey.
Single storey extensions are often about enlarging an open space like a kitchen-diner, allowing daylight to flood in through roof glazing and for it to be more informal. However, first-floor spaces are usually bedrooms and bathrooms, and adding an extension to the rear of a first floor can create awkward spaces, leaving rooms in the middle with no daylight and requiring wasteful areas of corridor.

‘They can also restrict the amount of daylight that a single-storey extension can bring into the heart of the ground floor. Such problems, however, are usually solvable when a skilled professional designer helps to work out the floorplan.’

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Side extensions

In many cases, two-storey side extensions should not be a problem, but it’s a good idea to discuss your proposals with the planners before spending money on drawing up detailed plans, especially if you are extending over two storeys. They will consider:

Footprint

There are few limits on the size of your extension’s floor area unless it’s likely to cover more than half the garden (including any existing extensions and outbuildings).

Height

You’re not normally allowed to build higher than the existing house. However, side-extension roofs and walls often need to be set back slightly from it (perhaps by 10–15cm).

Overlooking

Features such as upper-floor balconies can be contentious if they overlook the neighbours. For windows, you can use obscure frosted glass, install them at a high level, or fit skylights.

Overshadowing

Building a two-storey, or higher, extension too far out from the back of the house into your garden may overshadow the neighbours, which will limit the permissible size.

Highways

If your proposed extension could interfere with visibility for motorists, it will also limit how far out you can build.
‘Another factor to bear in mind when building within three metres (or in some cases, six metres) of neighbouring buildings is the Party Wall etc Act, which requires you to formally notify the adjoining owners two months in advance of the proposed project.’ Says Ian Rock.

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Matching your extension with your existing home

‘There is no hard-and-fast rule on what materials will be accepted by the planning office. It depends on the building, the area, local planning policy, and you — the homeowner,’ says Hugo Tugman.
‘It used to be that planners generally wanted extensions to be in keeping with the original building, which led to a rash of pastiche additions to older buildings, but these days there is more and more of a prevailing view that allowing an original building to be itself.

This single storey, innovative extension is clad in a blue render, and cost less than £100k,

‘Contrast does not have to mean shiny modern or hi-tech. It is generally a good idea when extending an old building for the extension to play a quieter role to that of the original building, and it is quite possible to produce a relatively contemporary design that is modest and calm in its expression.’

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How to create an open plan space

‘Open-plan or, more frequently, semi-open-plan living, is very popular, as it suits most people’s modern lifestyle and enhances the sense and use of space within the home,’ says Hugo Tugman. ‘I do generally encourage people to go this way; however, there are a number of things to bear in mind when working out how best to use the space.
‘It’s usually a good idea to identify different zones within your layout — such as the kitchen, dining and living areas. The look and feel of your space can be fine-tuned by the extent to which the boundaries of these are defined or blurred, and there are lots of devices, such as continuing through or changing the floor finish, for example, which can control this degree of separation.
‘While walls can block up an open space, they can be helpful when it comes to positioning furniture, storage and radiators, for example. One of the reasons that underfloor heating works so well in an open-plan space is because often there are not enough suitable walls on which to position radiators.’

Extensions with bi-fold doors

‘There is a range of different options available for bi-fold doors, from two-door models through to large eight-door configurations, set-ups for bay arrangements and entire 90-degree corner sections,’ explains Neil Ginger, CEO at Origin. ‘The price of bi-fold doors varies but, as a guide, a bespoke, aluminium design would cost from £1,200 per door leaf.
‘The space allowance for the doors to open outside depends entirely on their width. Bi-fold doors can be as narrow as 40cm, protruding less than half a metre outwards, while you will need to allow just over a metre of space for doors with a width of 1.2 metres.
‘Doors that open inwards are ideal for projects where space outside is limited — on a balcony, for example. In the majority of cases, it is recommended that outward-opening doors are chosen to prevent any rainwater from coming into the home when the doors are opened after it’s been raining.’
Bi-fold doors can also be installed internally, as the low threshold of the design can create a seamless transition from one room to another.’

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Building regulations for extensions

‘All home extensions need to comply with the building regulations,’ says Ian Rock. ‘Most obviously, this relates to structural stability — including foundations, window and door openings, lintels, beams and roof structures. Therefore, your design will normally need to incorporate a structural engineer’s calculations, submitted together with drawings as part of your building regulations application.
‘When it comes to submitting your application, you can either do this via local authority building control, or an independent firm of approved inspectors. Either way, there are two ways of making an application — either “full plans”, or the short-cut method known as a building notice.
For a major project such as an extension, it makes sense to get your design approved with the former before you start work, otherwise you could run into trouble if your project doesn’t comply with the regulations.

This industrial kitchen extension cost less then £100k and is flooded with light by a series of roof lights.

‘When work is due to start, it is essential to liaise regularly with building control, as they will need to carry out site inspections at key stages, commencing with start on site and excavation of foundations. Finally, once your new extension is built, don’t forget to obtain proof of compliance in the form of a completion certificate — this is a key document when you come to sell.’

What to submit to make sure you comply with building regulations

For all applications:

• Completed Building Notice form
• a plan to a scale of 1:1250 minimum showing the location, boundaries, drainage and sewers
• the appropriate fee

For a Full Plans application*:

• Completed application form
• estimate of costs
• the appropriate fee
• two copies of detailed drawings at a scale of 1:100 minimum
• two copies of a site plan showing the proposal, site boundaries and sewer positions
• two copies of any plans and specification to accompany drawings including structural design and calculations
• four copies of plans for buildings covered by fire safety legislation, showing fire resistance, fire detection, alarms, emergency lighting, means of escape and signage

*If online applications are accepted, only a single copy of each plan is required.

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Fireproofing a new extension

Most extensions should naturally comply with fire regulations thanks to the inert qualities of building materials such as plasterboard, bricks and concrete blocks, which can normally resist the spread of fire for at least 30 minutes,’ says Ian.
However, where you have any exposed major structural components such as timber posts and steel beams, they will normally need to be protected, for example with skimmed plasterboard lining. Also, where holes are cut in ceilings for recessed lighting, they may need to be fitted with fire hoods. Extensions built with modern timber-frame wall panels are lined internally with inert plasterboard and also incorporate integral cavity barriers to slow the passage of smoke and fire.
If your design includes an integral garage, then the walls and ceilings need to resist fire — which most materials should manage, although special pink- coloured plasterboard (fireboard) is the ideal cladding for ceilings and stud walls. Ceilings to integral garages must be plastered, and any doors from the house must be fire doors with a suitable step down into the garage (normally 10cm).
Requirements become a lot more demanding for extensions of three storeys or more. Considered as part of the newly enlarged house, this might involve fitting special fire doors to all new and existing rooms as well as ensuring there is a safe escape corridor (usually via the landing and stairs) down to a main exit door, with the stairs protected with a fireproof lining.
‘If your extension is two storeys or higher, it is best to assume that you need to fit a mains-operated smoke alarm to the upstairs landing(s) in the newly extended house.’

Where to begin your extension

Building materials

• BRE
  Expert advice from building research professionals
• GreenSpec
  Green-building resource with directory of materials for sustainable construction
• Self Build
  Site produced by Travis Perkins with links to materials suppliers
• SPAB
  Guidance on historic building materials from the Society for the Protection of Ancient Buildings

Decorating

• Crown Paints
  Advice on painting and decorating, plus a link to the My Room Painter visualisation app
• Dulux Room Painter
  Try out colours on screen in roomsets
• Dulux Trade Paint Expert
  Product and decorating advice, tips and colour tools

Expert advice

• Homebuilding & Renovating magazine
  Information, inspiration and source books for improvements, including extending
• RICS
  Guides on extending, party walls and right to light from the Royal Institution of Chartered Surveyors

Planning information

• Planning Portal
  Government information on planning and building regulations for England and Wales
• Planning Portal Northern Ireland
  Planning permission advice in Northern Ireland
• The Scottish government
  Guidance on planning and link to eplanning.scotland.gov.uk online planning applications service

Professionals

• Architects Registration Board
  Official UK register of architects; find one by name or region
• Chartered Institute of Architectural Technologists
  Find an architectural technologist, either regionally or by postcode
• Federation of Master Builders
  Search for a vetted builder by specialism and area
• Find an Engineer
  Search for a structural engineer; service from the Institution of Structural Engineers
• Kitchen Bathroom Bedroom Specialists Association
  Find an independent kitchen, bathroom, bedroom and home-office retailer
• RICS
  Find a local surveyor service
• TrustMark
  Search for local tradespeople including builders, plumbers and electricians who comply with government-endorsed standards
•  
•  
•  
• source ; https://www.realhomesmagazine.co.uk/advice/ultimate-guide-to-extending-your-home/

 

Why sight lines are key to good home design

 

Blogger Hannah Davey explains why creating clear sight lines through her new-look family home was so important. Plus, watch our video on creating a view right through your home

By Hannah Davey on

Many, many month ago, when the renovation was a rose-scented fairytale, and our heads still filled with endless possibilities of creating the perfect habitat to raise our children, we wrote our now infamous wish list. Back then, I had plans to be more delicious than Ella in the kitchen, and my better half was going to cultivate the garden than Alan Titchmarsh.
Sadly, Father Christmas wasn’t able to deliver many of our plans as the budget nose-dived. However, some details of the redesign were sacrosanct – and sight lines were one of those.

Sights lines are what you can see from any given point in your house – either into other rooms, or outside through windows or doors. In home design, you can use sight lines to draw attention to specific architectural details or views.

We wanted to create a home that flowed organically and allowed the glorious light that floods the hallway to permeate as far as possible. We also wanted to be able to open the front door and see way beyond the hallway – into the kitchen, the garden and towards the fire.

In the end, we had to fight hard over many decisions to keep the sight lines we wanted. Standing your ground with a builder is exhausting and through the project I have certainly learnt when to give in, but also when to dig some four-inch stilettos in the ground and not budge! The angled wall in our hallway was a stiletto-stabbing example.
The measure of success is subjective, but for us it comes down to what you can see, whether you want to explore, and whether it’s exciting, inspiring or homely.
We’ve tried to combine well-established interior styling techniques, like layering and texture, with a backdrop of light, space and structure. And having the sight lines is a key part of that.
If you’re thinking of creating a through view in your home, take a look at our video guide:

https://youtu.be/hZP-EztdVh0 

  Creating Plans for Buildings Regulations

 

Chartered surveyor Ian Rock bravely gets to grips with the task of creating his own Building Regulations compliant drawings — a task that takes him five days of ‘study exile’

By Ian Rock 

Last month, my wife Ewa and I found ourselves in a bit of a quandary while preparing plans for our new extension. I was keen to try my hand at preparing the detailed drawings for our Building Regulations’ application, but with professional CAD packages costing well into four figures, the sums simply didn’t add up.

Factor in the cost of your own time, and it makes a lot more sense to appoint a professional to do the job for you. But in this instance, I was determined to learn a new skill and prepare my own drawings.
After more research, my hopes were raised when I came across a possible solution — Arcon’s 3D Architect Designer software looked like it might fit the bill, with a range of packages priced from £150 to £550. After speaking to Tim Bates at Elecosoft (the company behind the software), I took the plunge and opted for Arcon Evo, a well-reviewed CAD package specifically geared to ‘building design and floorplans’.
After five days of self-imposed ‘study exile’ I emerged pale and blinking into the daylight, proudly clutching a set of professional-looking drawings. My efforts were greatly assisted by the facility to import existing scale drawings and trace over them using guidelines, thereby ensuring continuity with the planning drawings.

Creating Detailed Drawings

To my great satisfaction, it was now possible to print out multiple copies whenever required. Although the same result could have been accomplished in a fraction of the time by drawing plans by hand, the real bonus comes if you need to make any amendments, produce working drawings for the builders, or produce more detailed drawings of specific areas, such as foundations or floor joists, using an earlier copy as a template.
To avoid cramming all the details on one A1- or A2-sized sheet, I submitted the following additional information on separate documents:

Thermal insulation compliance

This lists the U values you aim to achieve for each thermal element of the building — the walls, roofs, windows, doors and floors. The performance obviously depends on the choice of construction materials and how easily heat passes through them (the ‘lambda-value’ or ‘K-value’) as well as the type and thickness of the insulation. Fortunately, there are plenty of online calculators available, such as the one on Kingspan Insulation’s website.

Span tables

The span and spacing of floor joists, roof rafters and flat roof joists will normally be calculated by your structural engineer, although there are span tables online that you can view for reference (try rightsurvey.co.uk/joist-span-tables-for-floor-construction). Alternatively, if you provide the manufacturers of I-joists and beam and block floors with your drawings, they should be able to provide the necessary calculations free of charge.

Window-to-floor ratio

The combined area of all new glazing in an extension (e.g. windows, doors and rooflights) should total no more than 25% of the internal floor area (after deducting any existing openings covered over by the extension from the total area of new glazing). The proposed total area of new glazing on our extension, at 35m², far exceeds the 28m² allowed to us under the ‘25% rule’ (based on 112m² gross internal floor area).
Happily, factoring in the total area of existing windows and doors engulfed by the extension buys us an additional 7m² — just enough to comply! Where your design exceeds this, you will need to provide some form of justification, usually achievable by beefing up thermal efficiency elsewhere in an extension.

Time-Saving Measures

The job of the drawings is to tell building control in diagram and text form how each specific part of the building is going to comply with the Buildings Regulations. But no matter how much of a CAD genius you are, there’s no point trying to illustrate complex design details that already exist in diagrammatic form. Fortunately, Arcon programs can import ‘ready-made’ detailing.
There is an excellent website for this purpose, BuildingRegs4Plans.co.uk, where, for a small fee, you can download a wide selection of diagrams and incorporate them in your plans. This saves you having to scour through the Approved Documents (the Department for Communities and Local Government’s hefty guidance on ways to meet Buildings Regs) to try and locate relevant diagrams. You also get access to a lot of useful Building Regs compliance text which can be copied and pasted to populate your drawings (and edited if required).
In the end, our completed application comprised a set of 16 A3-sized drawings (mostly 1:100 scale). In addition to those showing the main elevations, floorplans, sections and site layout, it was a simple job to print off additional sheets with details of drainage, ventilation and floor structures — thanks largely to the availability of ready-made diagrams and pre-formulated chunks of text.

Submitting Plans to Building Control

In my local authority, the fee payable for a Full Plans application depends on the projected floor size. As it was, we ended up with a total bill of £880, comprising an initial £320 charge payable up front, with the balance paid as an ‘inspection charge’ around the time of the first site visit. The alternative Building Notice route is now 20% more expensive, presumably in a bid to put people off using the ‘short cut’ method.
There was just one key document left outstanding, probably the most important of all — the structural engineer’s calculations. However, before our drawings could be completed there were a couple of structural issues I first needed to get some advice on. My next task was to find a tame structural engineer…

 

 

 

The proposed drainage plans for the ground floor of his extension

 

 

 

Which Wall Material Has the Best U Value?

What are the U values of different wall materials? Understand that, and you are well on your way to making your self build or renovation as thermally efficient as possible, says sustainable building expert Tim Pullen.

 

What exactly is a U value and why do architects, self builders and energy-efficiency experts get so excited about it?
Put simply, U values measure how easy it is for heat to pass through a structure (or its ‘thermal conductivity’), so the lower the number the better. To put it another way: low U values mean that only a small amount of heat is escaping through your walls, windows or floors.
To put that into context: a single-glazed window will have a U value of 5.0, a standard double-glazed window around 1.6 and triple glazed around 0.8. Building Regulations require a wall of no worse than 0.3, roof 0.16, and ground floor 0.22.
All of these U values are written as W/m²K. That is, Watts (of heat) passing through every square metre (m²) for each 1°C temperature difference (between the inside and outside of the building). The U value is therefore a measure of thermal efficiency. While that is important, it is only one measure of thermal efficiency and should not be considered on its own.

U Values of Different Wall Types

Each element of a wall will have an R value — the measure of its thermal resistance. To arrive at a U value we need to consider all the components. Taking a simple wall, and working from the inside to the outside, we might have 12mm plasterboard, 100mm concrete block, 90mm insulation in the cavity with a 110mm brick outer skin. Thickness matters, as the thicker the material the more it resists conducting heat.
If we take the R value of all those materials, at those thicknesses, and do some clever maths (there are websites that will do it for us) we get a U value for that wall of 0.3W/m²K — which is Building Regulations standard.

The brick and block walls of Paul and Angela Dallas’ stone and timber-faced Passivhaus property (also pictured at the top) in West Yorkshire achieve U values of 0.117W/m²K. Green Building Store provided technical support and eco products

Brick and Block Cavity Wall

The wall described above is the standard for masonry construction, with the ‘cavity’ filled with mineral wool insulation, giving a wall thickness of 312mm. Clearly, then, this is a solid wall (the cavity is filled, so is no longer a cavity, which is fine with Building Regs).

• U Value = 0.3W/m²K

Timber frame

In recent years the timber frame industry has moved from a 90mm stud for external walls to a 140mm stud — partly to deliver a better U value. The standard construction includes 140mm mineral wool insulation, giving a U value of 0.29W/m²K. With an external skin of timber cladding, brick slips or render installed, the overall wall thickness could be just 225mm.

• U Value = 0.29W/m²K

Structural Insulated Panels (SIPs)

SIPs are essentially two sheets of OSB (oriented strand board) sandwiching and bonded to insulation — normally polyurethane, polystyrene or, more rarely, mineral wool. Some SIPs offer hemp or other natural insulation options, but these are expensive and not common.
A 140mm standard SIPs panel will give a U value of 0.19W/m²K and an overall wall thickness of 220mm. The reason for the difference between SIPs and timber frame (which are otherwise very similar construction) is the difference between mineral wool and polyurethane. Interestingly, if the SIPs use expanded polystyrene in that same wall, the U value rises to 0.27W/m²K.

• U Value = 0.19W/m²K – 0.27W/m²K

Wall thickness was a priority on this SIPs build, which sits on a narrow site. The Kingspan TEK® Building System was specified by the self-builder. The SIPs were sourced from SIPS@Clays, who provided the erection team

Insulated Concrete Formwork (ICF)

These insulated blocks or panels are assembled on site and filled with reinforced concrete. The insulation is typically expanded polystyrene, and having insulation inside and out gives a U value of at least 0.2W/m²K, with a wall thickness of 250mm. Some systems offer the option to increase the internal insulation and can provide a U value as low as 0.11W/m²K, with a wall thickness of 335mm.

• U Value = 0.11W/m²K – 0.2W/m²K

Costs of Different Wall Types

Assuming the same outer wall finish, the average costs for different wall types will be:

• Brick and block: around £70/m² with a U value of 0.3W/m2K
• ICF: around £65/m² with a U value of 0.2W/m²
• Timber frame: around £65/m² with a U value of 0.24W/m²
• SIPS: around £70/m² with a U value of 0.19W/m²

ICF and SIPs give inherently better airtightness, so they give better thermal performance for around the same price as timber frame and brick and block.

As well as impressive U values, ICF can also be used to create homes with interesting wall shapes, such as those used in the award-winning ‘Curly House’ by ICF supplier Nudura in Sussex. The company offers its customers a one-day training course and site visit to witness ICF building in action

How to Improve U values

Obviously, the insulation material will improve the U value. The best currently available is the Val-U-Therm system (available from Scotframe) with a U value of 0.09W/m²K from a wall thickness of 235mm, plus the outer skin. Changing the 140mm mineral wool in a timber frame to 140mm polyurethane would give the same U value as a SIPs panel.
Similarly, change the concrete block inner skin of a brick and block wall to an aerated block and use polyurethane instead of mineral wool in the cavity, and the U value will improve to 0.21W/m²K. In other words, the desired U value can be achieved by a bit of juggling.

Off-site construction and U Values

On-site construction tends to be a less than perfect process. Materials will also have an impact: mineral wool tends to slump in a timber frame, leaving gaps; rigid insulation is seldom cut to be a perfect fit between the studs it is to fill; cavity-fill insulation may not be an airtight fit to the inner block skin.
It is impossible for design calculations to take these imperfections into account and houses tend to have a slightly worse U value than anticipated. The more that can be done off-site in a factory, the more likely it is that the design specification will be met, which is where SIPs and ICF score.

Richard Baker chose Potton’s closed panel timber frame system for his timber frame kit home project on the Isle of Man. Using 120mm Kingspan insulation, he achieved U values of 0.15W/m²K for the walls. The triple-glazed windows from ecoHaus Internorm provide U values of 0.8W/m²K

U Values and Building Regulations

The U values stated as ‘Building Regulations standard’ are the elemental U values and even if those figures are all met, the building will not pass the SAP (Standard Assessment Procedure) assessment for energy consumption and CO₂ emissions.
The design has to do better than all of these figures to meet SAP requirements and a wall needs to be nearer 0.25W/m²K than 0.3W/m²K to comply. Achieving that in a brick and block wall will increase the wall thickness by at least 50mm, and costs will rise. With all other construction systems, that lower U value is met as standard.

A Final Note on U Values

U values are important but thermal efficiency – reducing the energy demand and the property’s running cost – is becoming increasingly important and means addressing airtightness and thermal bridges as well. A good U value will not compensate for a leaky, poor-quality build.
Starting with a construction system that gives a better U value and airtightness, as well as eliminating thermal bridges, makes obvious sense.

 

 

By Tim Pullen

source : https://www.homebuilding.co.uk/which-wall-material-has-the-best-u-value/