In this blog, I talk about Building Regulations. During the many seminars that I have spoken in and the workshops that I run, I have a section dedicated to this subject. However, it never fails to surprise me how many delegates are simply unaware of these important construction regulations.
In this Blog I give an overview and discuss Part A Structure.
Since setting up my Architectural practice in 1995, the building regulations have changed enormously, in fact, they first came out in 1991.
So, what are they and how do they affect you?
The Building Regulations are a set of Documents approved and issued in the UK by the Secretary of State for the purposes of providing practical guidance for some of the more common building situations. They set minimum standards for the design and construction of all buildings and require that any work should be carried out with proper materials and in a good workmanlike manner and they are made for specific purposes, these being Health and Safety, energy conservation and the welfare and convenience of disabled people.
The regulations are set out in a series of sections known as ‘Parts’ and are there to ensure that national standards of building work are being undertaken whether it be a small house extension, a new house, a new factory, office or your house renovation.
The regulations are administered by either your Local Authority Building Control Section or by what we term ‘Private Building Control surveyors’ and you are required to make an application (and pay a fee) if the work you propose to undertake falls within what is known as ‘relevant works’ or you are making a ‘material change’ to the building.
For most light refurbishments or renovation works where you are replacing a bathroom, kitchen and perhaps inserting a dpc it is not necessary to submit an application, however where people fall foul is that the Approved Document Part L which relates to Conservation of Fuel and Power applies should you hack off 25% of the external render or Internal plaster of an external wall.
The update to that ‘Part’ which was in 2006 requires that as you are ‘replacing or renovating a thermal element in a building’ ie a wall, then you have the opportunity, to improve the insulation value of that wall by adding either External or Internal wall insulation.
Now that you have fallen into the realms of the Building control section as you are undertaking ‘relevant works or making a material change’ they will be interested to know what ‘other’ work you are undertaking to ensure that it meets the required standards.
Now, in all honesty, this is nothing to be concerned about providing you are doing the work properly and in good workmanlike manner, after all should your refurbishment project be such that you intend to sell on, your purchasers surveyor will pick up upon the fact that you may have done ‘relevant works’ or made a ‘material change’ and may stipulate to the lender that you provide the necessary Building Regulations Completion Certificate.
If your not sure if the work you are undertaking falls under the Building Regulations, Call your local Office. Making an application retrospectively can be costly.
So, what sections of the Building Regs do you need to be aware of to ensure that you stay within the law and avoid you project going over budget?
The main Parts that affect Renovations and Refurbishments are:
Part A –Structure
This Part deals with the structural stability of the building and covers foundations, floors, walls (internal and external) and roofs.
Foundations: If you are looking to knock down a wall and install a steel beam, you may find that an internal wall remaining that you intend ‘bearing’ is not strong enough to carry the addition ‘point’ load. Think of it like a woman’ shoe, the sole part of the shoe can spread the load, whereas the stiletto is concentrating the load. If the stiletto is too slender it will collapse and if the base it is pressing on is too weak it will punch through (subside).
So, it may be necessary to build a small pier or column in blockwork, this will have to sit and be built off a small concrete foundation, usually 600x600x225mm, and will need to be dug into the original ground.
If you need to replace an existing solid floor or are replacing an old timber floor with a new solid concrete floor, this construction must include a sub-base (hardcore) and a DPM, Insulation and the concrete slab itself. Some people will lay a sand cement screed (50mm) over the slab to get a level finish. The insulation to be installed will be guided by the BCO, the requirement for the thickness in a new build is determined by other factors, so in a refurb, any amount of insulation is better than what was there before i.e. nothing. It’s normal to add at least 100mm of polyurethane insulation. (see image) This insulation can be placed either above or below the DPM. The concrete floor must also be of a suitable mix and the sub-base must be at least 150mm thick and compacted.
Removing Internal load-bearing walls:
If you intend removing a wall to make a room larger and the wall is load-bearing, meaning it is carrying either the floor above or a solid wall above, then you will need to insert a beam or RSJ (rolled steel joist) to be able to ‘carry’ the load from above. For this you will need to submit an application and provide calculations from a structural engineer to prove that the beam is adequate to carry the imposed loads, however I have found that from my experience and that of the Building Inspector that we can agree on-site that a particular RSJ size would be satisfactory to do the job, so, by all means, ask your Inspector if he is able to advise you of an acceptable size beam, before you go spending £250 on structural calculations.
In addition, there are companies such as Catnic and IG Lintels who supply fabricated beams and are catalogued as being suitable for internal openings both load-bearing and non-load bearing, light-duty and heavy-duty and are sold based on the loading and length. So, for example if you are opening up a room and the span of the opening is 3m, you may find that a ‘light duty’ beam may only go up to 2.4m, therefore you need to choose a ‘heavy-duty beam’ these companies will provide a technical service where they can advise in ‘typical domestic’ situations which beam will suit the particular requirements.
In the picture above, I show a situation where I have constructed a pad foundation to take a new blockwork pier, which carries a proprietary steel lintel. Also, I have excavated the old floor which did not have a DPM and laid new hardcore, a new DPM and then Polyurethane insulation before laying a new concrete slab over the top.
Look out for my next blog where we will cover Part B – Fire through to Part P – Electrical.
Mike’s Top Tip!
“Taking the time to understand the relevant Building Regulations will save you time and money on all your projects.“
Why not check out the new edition of my book which has a complete section on building regulations and some great real-life case studies.?
Get your copy here http://www.propertyexpertpartnership.com/book
Thanks for reading!