My House Extension - Building Regulations

No matter whether you require planning permission or not for your build, you will definitely need to follow building regulation laws.

You do this by letting your local council building control department of your intentions. You will need to pay for this involvement which includes a number of site visits at various stages of the build.

As with the planning department, you should go and visit your local building control department and take them through your plans. They will tell you how much you have to pay (based on the size of your build) and answer any questions you might have about the build - size of foundations etc.

This is not the same as planning permission, but is the control of building works for fire resistance, structural stability, ventilation, thermal insulation and drainage.

As different regulations apply, you may need a separate permission from the Council before you can start work. Building Regulations Approval is not normally required for some single storey extensions under 30 square metres such as conservatories (provided they have a fully glazed or translucent roof and have certain glazed panels of laminated or toughened safety glass), or car ports which are open on at least two sides.

One of their best pieces of advice is: It’s always a good idea to talk to your neighbours about your proposal before starting work.

Details of how much you will need to pay are obtainable from your local council but some of my local council's explanatory notes can be seen by clicking on the picture above and précised below.

FEES are payable as follows:

If you submit Full Plans yu will pay a plan fee at the time of submission to cover the costs of approving or rejecting them.
With Full Plans submissions, for most types of work, an inspection fee covering all necessary site visits will be payable following the first inspection.
If you submit a Building Notice, the appropriate Building Notice fee is payable at the time of submission and covers all necessary checks and site visits. The Building Notice fee is equivalent to the relevant plan fee and inspection fee combined.

Table 1: Fees for small domestic buildings, e.g. certain new houses and flats. These apply where the total internal floor area of each home, excludin9 any garage or carport does not exceed 30m^2.

Table 2: Where work involves more than one domestic extension, the total internal floor areas of all storeys of all the extensions shown on the application should be added together to determine the relevant fee. If the extensions exceed 60m², then Schedule 3 applies.

Table 3: Applicable to all other building work not covered by Tables 1 or 2. The 'total estimated cost’ means an estimate we accept as being of a reasonable cost that would be charged by a person in business to carry out the work shown or described in the application. This excludes VAT and any professional fees paid to an architect, engineer or surveyor, etc. It also excludes land acquisition costs.

What is the difference between a 'full plans' and 'building notice' application?

Full plans: You must send full plans application if the building is used for a ‘relevant use’ and Part B of Schedule 1 (fire safety) applies to the work you are planning to do. ‘Relevant use’ means that the building is used as a workplace and Part 2 of the Fire Precautions (Workplace) Regulations 1997 applies to it, or a use listed under Section 1 of the Fire Precautions Act 1971 (this includes shops, offices, hotels, hostels for hotel staff, boarding houses and factories).

Building notice: If Part B of Schedule 1 (fire safety) does not apply to the work, or the building is a house, flat or institution (for example, a hospital), you can use a building notice application instead.

As far as I understand it, you can keep things simple and low cost for building a small extension by using a building notice where you do not need to submit full plans.

An example of a simple Building Notice form can be seen on the right (click to see the full size version).

Issue 1 - drainage inspection chamber: The principle issue I wanted to talk about was concerned with a main drainage inspection chamber. At present this is outside of the house but will within the new extension.

I just wanted to check that this would not be an issue and a quick search on the Internet showed that you could buy good sealed manhole covers. It turns out that it is not a problem as long as an internal, sealed, cover is used and the pipes, where they go underneath the foundations are handled correctly. More on this elsewhere, but the foundations should finish either side of the pipes, be surrounded by gravel and bridge with a slab of some sort.

Issue 2 - windows: One of the biggest issues I face is the question of what window I could use in the new extension. The rest of the house uses wooden window frames with real lead windows with secondary glazing.

Since 1995 there have been strong regulations concerning heat loss. These regulations stipulated that double glazing is required for all new windows.

In 2002 building regulation changes stipulated that even replacement windows as well as new windows are required to meet the new standards as well.

It was confirmed that I would need to have double glazing in my new window which will be a big issue for me as I want the window to match the rest of the house. To achieve this, I will need to build the window myself. There will be much more on this later I'm sure.

Issue3 - roof line: I also wanted to check the roof line of the new extension. To determine the width of the extension I needed to do a quick mock-up of the roof line and the new outside wall. The roof line is determined by the line and slope of the existing roof coming down to meet the wall. The wall needs to clear the existing drain and high enough so that the gutter is above head height. Everything has to be juggled to get the optimum mix.

Issue 4 - foundations: I also wanted to check on the size of the foundations required. Where I live, the subsoil is rock-hard sand about 100mm (3") below the service. So the the foundations should be 600mm (24") wide at a depth of 600mm so that they can't be affected by frost.

The building control staff were very helpful and friendly and were quite prepared to answer any questions I had. As they visit a build on a regular basis for inspections it is quite important to keep them involved on an on-going basis. The last this I want is to be told to knock something down that I've spent a lot of time building!

It was also mentioned that the extension would need an extraction fan in the toilet.

19th February 2007: Once I have clearance from the planning department, I will submit the building notice form together with my sketches.

Stage		Description
Stage 1		Commencement
Stage 2		Foundation excavations (before concreting)
Stage 3		Foundation concrete (concrete laid)
Stage 4		Oversite filling and mesh
Stage 5		Damp Proof Course
Stage 6		Drain before covering
Stage 7		Drain test after covering
Stage 8		Floor joist
Stage 9		Roof construction
Stage 10		1st fix electrical installation
Stage 11		Occupation of building
Stage 12		Completion of building