The Headline Programme
For a bespoke home in our four counties, allow 18 to 30 months from owning the plot to holding the keys. Roughly six to twelve months of that is design, planning and pre-construction. Twelve to eighteen months is on site, depending on size and complexity.
- Feasibility and brief: 4 to 6 weeks.
- Design development to a submittable scheme: 8 to 12 weeks.
- Planning determination: 8 weeks for householder applications, 13 weeks for major schemes, longer where committee or consultation extends it.
- Technical design, engineering, building control and pricing: 8 to 16 weeks, ideally overlapping the planning period.
- Construction: 9 to 18 months for most new houses.
- Commissioning, snagging and handover: 3 to 6 weeks.
Where Programmes Actually Slip
Very rarely in bricklaying. The delays that hurt are decisions not made, information arriving late, and surveys commissioned in the wrong order.
- Planning conditions that require information before commencement, which stop a start date dead if nobody read them early.
- Utility connections, where lead times are measured in months rather than weeks.
- Party wall awards on attached properties, which cannot be rushed.
- Long lead items such as glazing, structural steel, bespoke joinery and heat pumps.
- Client decisions on kitchens, bathrooms and finishes, which have a real deadline whether or not anyone has said so.
Why We Front Load the Work
Our pre-construction stage exists to remove those risks before the programme starts running. Design coordinated, engineering finalised, trades engaged, long lead items ordered and the sequence agreed. A build that starts fully resolved finishes on time far more often than one that starts early.
Extension and Conversion Timescales
Extensions are quicker but the pattern is the same. Allow three to five months of design, approvals and pricing, then time on site: 3 to 5 months for a single storey extension, 4 to 7 months for double storey, 5 to 8 months for a wrap-around, 10 to 16 weeks for a loft conversion, and 6 to 14 months for a basement.
What You Can Do to Speed It Up
Commission surveys early, settle the brief before design starts, make finish decisions on schedule, and appoint a single team responsible for design and construction so nobody is waiting on anybody else. Start with the project calculator so the budget conversation happens at the beginning rather than three months in.
A build that starts fully resolved finishes on time. A build that starts early almost never does.
Key takeaways
- Allow 18 to 30 months from plot purchase to handover for a bespoke new home.
- Planning determination is 8 weeks for householder and 13 weeks for major applications.
- Programmes slip on decisions, utilities, party walls and long lead items, not on trades.
- Overlapping technical design with the planning period saves real months.
- Extensions need 3 to 5 months of preparation before any time on site.
About the author
Kevin Edge founded Mosaic Bespoke and has spent more than two decades in planning, design and construction, working with private clients and landowners across Hertfordshire, Buckinghamshire, Bedfordshire and North London.