Planning your project
Planning a Building Project in Bexley and Nearby
The order it actually happens in, how long each stage really takes and what causes the delays. Written for people who have never done this before, which is nearly everybody.
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Before anything else
The paperwork takes
longer than the build
A single storey rear extension takes ten to twelve weeks to build. Getting to the point where somebody can start it takes six months on a good run, and that gap is where most of the frustration in this process lives.
Almost none of that time is anybody being slow. It is a design stage, a statutory determination period, notice periods fixed by an Act of Parliament and a builder's diary, mostly happening one after another rather than at the same time. Knowing the order is what lets you overlap the parts that can overlap.
This page sets out that order, how long each part takes and what causes the delays. It is not legal advice and we are builders rather than planning consultants. Your architect confirms what applies to your address, and the council decides.
What we can tell you is what we watch go wrong. Most of it is avoidable and almost all of it happens before anybody picks up a tool.
The sequence
Eight steps,
in this order
Steps five and six sometimes run alongside each other. Everything else happens one after another, whatever anybody promises.
01 / Work out what is actually wrong
Not what you want to build. What is wrong with the house as it stands. People arrive with a solution already chosen and it is frequently not the cheapest answer to their own problem. A loft conversion and a rear extension both add a room, and only one of them costs you the garden. Write down the three things that irritate you most about living there and start from those.
02 / Get a realistic budget before a drawing exists
This is the step most often skipped and it causes more abandoned projects than anything else. An architect will design what you ask for. If what you ask for is twice your budget you will find out after you have paid for drawings. Look at the ranges on our costs page first, then design to a number rather than discovering one.
03 / Appoint an architect or designer
They design the scheme, prepare the drawings and submit the application. Ask to see work they have done on your kind of house, ask what their fee covers and specifically whether it includes dealing with the council after submission. It usually does. It is worth having in writing.
04 / Measured survey and existing drawings
Somebody measures the house properly and draws it as it is. Every drawing that follows is built on this, so an inaccurate survey is expensive later rather than cheap now. On an older house it is worth paying for a proper one rather than working from an estate agent's floor plan.
05 / Planning permission, or a certificate of lawfulness
If the work needs permission, the application goes in here. If it falls under permitted development, it is worth applying for a lawful development certificate anyway. It is not compulsory. It costs less than an application. And it is the document a buyer's solicitor asks for in ten years, when nobody can remember what was agreed.
06 / Structural engineer
Once the layout is settled, an engineer sizes every beam and specifies the foundations. This can run alongside the planning application on a straightforward job, and cannot on a complicated one, because there is no point calculating a scheme that might change. Your architect will tell you which yours is.
07 / Building control and party wall notices
Building control is arranged before work starts, not during. Party wall notices need serving with real time in hand, and the notice periods are set by statute rather than by agreement. This is the step that catches people out, because it is the one with a legal clock on it.
08 / Get quotes, then book the work in
Give every builder the same drawings and the same specification, or you are comparing three different jobs. Then expect to wait. Any builder worth using is booked months ahead, and a builder who can start next week on a job this size is telling you something.
How long each part takes
Where the
time actually goes
Two of these are set by statute and cannot be shortened by anybody. The rest are down to how quickly decisions get made.
Design and drawings, 4 to 10 weeks
From appointing an architect to having something ready to submit. It depends far more on how quickly you make decisions than on how quickly they draw. Couples who disagree about the kitchen add weeks here without noticing.
Planning determination, 8 weeks
The statutory period for a householder application in England is eight weeks, and it runs from the date the council validates the application rather than the date you submit it. Validation means every form, drawing, certificate and fee has been checked and accepted. Allow ten to twelve weeks from submission in practice, and longer if the council asks you to agree an extension.
Party wall notices, 1 or 2 months
Set by the Party Wall etc. Act 1996 and not negotiable. Two months' notice for work to an existing party wall or structure, and one month for building on the boundary line or for excavating near a neighbour's foundations. Your neighbour has fourteen days to reply. If they do not consent, surveyors are appointed and an award is drawn up, which adds several weeks.
Structural calculations, 2 to 4 weeks
Quick on a simple job and slower where the engineer needs to see what is behind the plaster before committing to a design. Sometimes they cannot finish until the building is opened up, in which case the calculations arrive in two parts.
Building control, arranged in days
Setting it up is fast. What takes time is the inspections themselves, which happen at fixed points during the build and have to be booked. The completion certificate comes at the end and it is the document that matters. Keep it somewhere safe.
Waiting for a builder, 2 to 6 months
The part nobody plans for. Get your quotes while the application is with the council rather than after it comes back, so you are in a diary rather than starting a search. Approval lasts three years, so there is no rush once you have it.
What goes wrong
Six things that
add months
All six are avoidable and we watch every one of them happen more or less every year.
An application that was not valid on submission
The eight week clock does not start until the council accepts the application as complete. A missing form, the wrong fee or a drawing without a scale bar can sit for weeks before anybody tells you. This is the single most avoidable delay in the whole process and it is entirely in your architect's hands.
Changing your mind after the drawings are done
Moving a wall on a drawing is cheap. Moving it after the engineer has calculated the beams means recalculating them, and after submission it can mean a fresh application. Make the big decisions early and hold them.
Serving party wall notices too late
Two months is two months. If the notice goes out four weeks before your intended start, your start moves. It is the most common reason a job that was ready to go sits waiting, and it is completely predictable.
Discovering the drainage runs the wrong way
Where a public sewer crosses the site, a build over agreement with Thames Water is needed and it is straightforward while the scheme is on paper. Found after the foundations are set out it is a redesign. Ask about it at the survey.
Underestimating what the ground will give you
Foundation depth follows the ground rather than the drawing, and trees, made ground and old fill can all add a metre or more. Trial holes at survey cost very little and turn a guess into a number. There is more on this on our costs page.
Choosing a builder on price alone
Three quotes that look different are usually three different scopes of work rather than three different rates. Read them line by line for scaffold, skips, foundation depth assumed, building control and the kitchen allowance. The cheapest quote is often the one with the most missing from it.
Our part in it
When to bring a builder in
Most people talk to a builder last, once the drawings are done and the permission is through. That is the conventional order and there is nothing wrong with it. It is not always the best one.
Coming to look at the house before the design is finalised costs you nothing and occasionally saves a great deal. We can tell you what the ground is likely to do, whether a lorry can reach the back, whether the drainage is where the drawing assumes, and roughly what the scheme in front of you will cost to build. Any of those can change what is worth designing.
It is not a substitute for an architect and we would not pretend otherwise. Design is their job and we are not competing for it. What we can do is stop a scheme being drawn that is twenty thousand outside your budget for reasons that were visible on the first visit.
There is no charge for that visit and nothing is attached to it. If you go elsewhere afterwards, you go elsewhere with better information.
Each kind of work has its own approvals detail on its own page. House extensions, loft conversions, garage conversions, chalet conversions and whole house renovations. Figures for all of them are on the costs page.
Next step
Start with
a conversation
Whether you have drawings, a rough idea or just a house that has stopped working, we will come and look at it and tell you what we are seeing. The survey is free, the quote is itemised, and no deposit is taken at any point.
Or call 020 3576 5639 or 07766 161063, or message us on WhatsApp.