House extension plans - are they really needed?

Most house extensions will require plans or drawings which show the existing and proposed details of the property to be extended.  Some smaller house extensions are built without any form of plans but this is usually at the low end of the market where the client and builder are taking a chance that the scheme is permitted development (no formal planning permission is required) and that both the builder and the home owner share the same vision of what is to be installed - all very dodgy!

So, who should be preparing these house extension plans and can you do it yourself? Firstly, having a successful house extension is not just about the plans or drawings.  This is just a small element of the normal professional service that most house extension designers or architects provide.

Most house extension plans are simply seen as a visual representation of what the finished extension will look like but this is incorrect.  All house extension plans serve a multitude uses.  They are required for Planning permission, Certificates of Lawful Development, Building Regulations approval, clients approval, neighbour consultations and of course to instruct your builder on what you want.

The level of detail that most house extension plans will include on them will vary during each stage of the design or approval process.  Planning do not require a high level of constructional detail unless the scheme is for a listed building.  Building Control require detailed constructional plans & specifications but do not require any terms of contract details.

Your builders tendering for the works require everything - this will be the basis of there price for the works so it is important that the drawings and accompanying specifications have a high level of detail, clarity & accuracy.  Skimpy, half-baked incomplete plans without separate specification manuals will be a recipe for disaster for both the client and the builder alike.

This is where the experienced and professional home extension designer or architect comes into their own.  They will ensure that your documentation is complete and as concise as it can be so that your builder prices for all the works required and excessive claims for extra costs do not arise.

The 'cowboy' plans drawn people offering house extension plans services usually fall short of this element of the works and can leave you very exposed.  Would you employ a journalist hack to write your last will and testament? No, of course not as these are very precise legal documents giving instructions to the people you leave behind.  The same logic applies to home extension plans - use the correct professionals for the relevant job.