The art of estimating within a set of defined tolerances.
ESTIMATED BUDGET BUILDING COSTS
Estimating any building project is not an exact science as each builder has their own
pricing strategies and margin allowance which can lead to great variations in their quotations. This
makes estimating budget costs prior to developing the full scheme design very difficult and any estimated
costs offered by CHP should only be treated as very approximate and not as the maximum price expected which
can only be determined by a tender.
However, from previous experience there are a few common items that can affect
your extension building cost:-
1. The cost per square metre is significantly higher for smaller extensions
below 30 square metres.
2. Complex schemes and works that affect the existing structure will increase
the total building costs of the extension.
3. Bad ground conditions, trees and hedgerows etc. can lead to deep foundations
and a specially designed ground floor structure.
It has been my experience that current building costs for extensions generally
range from £1,500 to £2,000 per square metre plus VAT and other lump sums for appliances and fittings. We are
currently in a min-boom market for building works and building costs have risen substantially over the last 2
years. Many good builders are also very busy and you may even experience difficulty in obtaining a builder
that can start your project shortly after Building Regulation Approval.
When calculating the area of the extension for budgeting purposes it is wise to
use external measurements for each floor - not just the footprint area created.