Build cost | House extension | Loft conversion
Bronbuild Hersham Walton on Thames, Surrey KT12 4RW UK

what it costs

"Approximate build" prices are for the average dwelling and are  just that, each project is different in complexity a firm offer will only be given after onsite assessment and viewing approved drawings or Bill of Quantities, prices exclude all utility services from the highway to the dwelling (Not normally an issue with existing buildings).


advantages of having plans prepared first and waiting for the necessary consents

Building Regulations and Town Planning Regulations are complex and continually changing, unauthorised building work is a risky business, by working to accurate approved drawings you are more likely to avoid costly mistakes and the possibility of Local Authority enforcement proceedings.

By staying legal, you avoid the surprise of illegal work coming to light by solicitors/local authority searches, you will have the required approval documents to be included with your home information pack when you try to sell, avoiding unnecessary delays, frustration and possibly a lost sale.

Freedom to shop around for the best price from reputable builders by creating a level playing field which conveys the same information to all.Your Design Service Here


Loft Conversion - House Extension

Having obtained the required planning and building regulation consents you may be forgiven for thinking that you have all the consents you need. However the spirit of the Party Wall Act needs to be considered by the building owner " the person having the work done " and adjacent owners, aggreement between affected parties needs to be in writing, if in doubt look at the official guidance here Party Wall Act
Whaterver your home remodelling project please forward your approved drawings for a competative quote, any format will do pdf dwg dxf etc.

INDICATIVE APPROX BUILD COST depending on specification and other factors, the following examples are based on 3.00 meter projection from dwelling and a width of 6.00 meters of usable floor space ie. 18.00 meters square per floor.

Ground floor flat roof home extension GBP 36091 divided by 18=GBP 2005 M2

Two storey flat roof home extension GBP 55628 divided by 36=GBP 1545 M2

Ground floor pitched roof home extension GBP 40661 divided by 18=GBP 2259 M2

Two storey pitched roof home extension GBP 59603 divided by 36=GBP 1656 M2

Additional storey above existing ground floor same as respectve single storey

Loft conversion roof extension GBP 1481-2179 M2


Let your lender know of your proposal
Check for restrictive covenants that may apply to your property
Check that article 4 is not in force in your area preventing some normally permitted development rights
The Green belt , Conservation areas and Areas of outstanding natural beauty normally need special consideration check with Local Authority
Check the existing structure is strong enough to support the additional loading
Make sure the requirements of the Party Wall act have been dealt with properly
Get the necessary Building Regutation and Town Planning approvals before commencing any work
If you are connecting to or building over a foul drain serving more than just your property, you may need to consult with your water authority.
Protected Species, a wildlife licence may be required if the work will affect protected species like bats. If in doubt contact Natural England for advice