© 2007 Cadbox Ltd

Its a good idea to have as accurate picture of what you want to achieve at an early stage as possible. Its common for people to have last minute ideas of what they want - which always adds to the cost of a project & either builders annoyance or profits.

To avoid this at the start of the project we would usually draw up a document called a ‘clients brief’ where you roughly set out your ideas to give us general guidelines on how to proceed. We would also refer back to this if you made substantial changes that might cause us substantial extra work, and a revision of our fee.

For small or a simple project, a sketch plan may be sufficient to make a start, - its also wise to discuss your proposals with all users of the building and possibly neighbours to get their opinions on what you propose, and to get them on your side. Its also worthwhile running over our list as there may be some items such as  environmental features which you may not of considered.


Function, Budget, Appearance, Timescale



What you want from  your extension determines the size budget  etc.. Usually this is based on a plan, you could describe this to us, or may be able to do a rough sketch . The most economic plan for a building is usually a rectangle.

There may also be other factors you want us to take into consideration - if you plan to stay in the house for a long time, if you want to incorporate environmental factors etc..



Your budget is probably the main factor which will influence your proposals if you just want a cheap a job as possible it will influence all the other factors.

It is difficult to give an accurate cost for a house extension - without first having a plan drawn, & then you will only be able to get estimates based on areas.

Its usually when you have construction drawings that you can get a realistic quotation from a builder , and even then its wise to have at least 10% over this in available funds, to cover any unforeseen problems.

Generally you get more value for money- in terms of area/ cost  for a two storey extension- but expect to pay more in design fees.



So that you can convey your requirements its a good idea to compile a few sketches, photos or pictures from magazines that illustrate what youd like to achieve, - this gives us something to work to.

Generally the extension should be in proportion, and usually match its surroundings, however planners recognise that sometimes its difficult to match an existing style and may accept a more contemparay style- you may have a job convincing your neighbours of this, but it may be worth trying to get permission for what you really want.



You may have a deadline such as the arrival of  child & requirement for extra space which is influencing your decision to build.

You need to tell all parties this before you start. It can be very difficult to keep everyone to a deadline so they need to know in advance of any work.


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