The Institution of Structural Engineers
David Ryland
I.Eng. A.M.I.Struct.E.
Structural Engineer
TRADA member

 
Limited Guidance Notes on Extensions
 

Section C - Building Control Applications

 
1. Unlike planning approval, which is concerned with the outward appearance and dominant visual impact of a development, building control approval is concerned with the structural strength and heat loss of the elements which are used to construct the building and the ability of the structure to transfer load, including wind forces, safely to the foundations.
2. Once planning permission has been granted, it is only a matter of compliance with the relevant codes of practice and regulations, which affect building control, in order to obtain approval. The Department of the Environment has published a set of 'Approved Documents' which give general guidance on conforming to these complex regulations.

3. However, it must be stated that the detailed structural design of the proposed extension is of equal importance to the end product as is good planning.

4. There are two options available to a client regarding the method of obtaining building control approval. The first is to submit a 'Building Notice' application. The second is to submit a 'Full Plans' application.

5. Under a Building Notice, the Local Authority Building Control Officer (BCO) will attend site without necessarily having carried out a check of the structural design of the building. He will pass comment on his considered opinion of the main elements of the work such as depth of foundations, suitability of the ground in the exposed trenches and the provision of damp proof courses, membranes and other general matters of a similar nature. The BCO may call for design calculations for any structural members which he cannot check from his standard tables provided in the 'Approved Documents'. This may delay work on site until such calculations are approved. Building Notice applications are not usually approved or even checked.

6. The other option is to apply for 'Full Plans' approval. Under this method, drawings and calculations are submitted. These are checked by the BCO and another structural engineer. Approval is given in writing prior to work starting on site. If any problems are identified during these checks they can be discussed with the designer and rectified without disruption to the build programme.

7. Proceeding on a Building Notice is usually satisfactory for very small domestic projects where, perhaps, changes are being made to an existing building where solutions are developed 'on the fly'. David Ryland does not recommend this approach for larger projects which involve areas of design that, by their very nature, fall outside the scope of the 'Approved Documents'. Adjustments or alterations to the design which may be required as a result of the BCO design check, arising after the work has been carried out, are often difficult to rectify and generate delays and additional costs. This is not in the client's interest.

8. It is a condition of David Ryland's acceptance to carry out any design that 'Full Plans' approval is obtained from Building Control before materials are ordered or work is put in hand.

9. Any work that is put in hand, prior to the granting of such approval must be considered to be at risk. The risk is the responsibility, either of the builder, if he wishes to advance the programme for his own benefit, or the client if he instructs or permits building work before such approvals are obtained.

Contact details:
Email: david@extensions4homes.co.uk
Tel: 01953 853040
Mobile: 07802 183823

 Guidance Notes on Extensions 

 Permitted Development 
 Planning Permission 
 Building Control 
 Foundation Engineering 
 The Builder 

Sample drawings
Planning:   Drawing1   Drawing2 
   Drawing3   Drawing4 
Building Control:   Drawing1   Drawing2