House Extension Time Scales - What should you be expecting from inception to completion?

Many homeowners seem to forget that there will be a long lead in time before that can start their house extension on site.  A generous allowance needs to be made for the time scales on a house extension anything between four and eight months depending upon how you have broken the project down.

Assuming that you would want to play safe with your council applications and approvals by only moving on from one design stage to another here is a typical example of a house extension time scales & what you should be allowing:-

DESIGN STAGE 1:- Making your own schedule of requirements, viewing other extensions and completing some basic research = 1 week

DESIGN STAGE 2:- Interviewing a few experienced house extension designers or architects for assessment of their skills and charges = 2 weeks

DESIGN STAGE 3:- Engaging Professional home extension designer or architect an commencement of their survey and collection of site data = 2 weeks

DESIGN STAGE 4:- Presentation of first design scheme proposal by your design agent issued for your assessment and comments = 4 weeks

DESIGN STAGE 5:- Client assessment period and note taking.  Meeting with house extension designer to chat through queries, amendment of scheme & upgrade to Planning application standard = 4 weeks

DESIGN STAGE 6:- Submission to council planning Dept. for either a planning application or a certificate of lawful development.  Wait for decision notice = 8 weeks

DESIGN STAGE 7:- Upgrade of the planning scheme by your house extension designer or architect to full construction scheme with specifications and details etc. ready for the Building Regulations application = 4 weeks

DESIGN STAGE 8:- Homeowners assessment of all details of the construction scheme presented. Making notes and list of queries for any amendments = 2 weeks

DESIGN STAGE 9:- Submission of construction scheme to Council Building Control Dept. for approval.  Decision Notice arrives = 8 weeks

DESIGN STAGE 10:- Researching recommended house extension builders to approach for tender.  Making initial contact & sending tem the tender documents = 1 week

DESIGN STAGE 11:- Tender period.  Return of all tenders for homeowners assessment of prices = 5 weeks.

DESIGN STAGE 12:- Discussions with preferred builder to explore other contrast detail & possible start date. Due dilligence checks. Formal engagement of builder = 2 weeks

DESIGN STAGE 13:- Period of waiting for builder to start on site = 8 weeks

DESIGN STAGE 14:- Contract period for the works. Finish snagging and move in for use of extended house = 12 weeks

TOTAL TIME FOR FINISHED HOUSE EXTENSION:- from inception to completion = 63 WEEKS TYPICAL

Over a year I hear you ask? Well yes living in the real world and based upon 30 years experience.  You can compress this estimate typical time scale by conjoining several of the design stages above rather than adopting a 'step by step' approach and this could remove about 16 weeks of time but you may be exposing yourself to a greater level of abortive fees.