A house extension can give you the space you need without the cost and disruption of moving. But the build itself is only one part of the job. Good extensions start with a clear brief, realistic decisions and the right checks before anyone arrives on site.
If you are planning a house extension in Bromley, this checklist will help you get the important points in order.
1. Be clear about what the extension needs to achieve
Start with the problem, not the drawings.
Do you need a larger kitchen, an extra bedroom, a home office or a better connection to the garden? Is the priority more floor space, more natural light or a better layout?
A clear brief helps the designer and builder give practical advice. It also makes it easier to control the budget because every decision can be tested against what the project actually needs to deliver.
Write down:
- the rooms or functions you need
- what is not working in the current house
- your preferred finish
- any fixed dates
- your available budget, including a contingency
2. Check the planning position early
Some house extensions can be completed under permitted development rights, provided the proposal meets the relevant limits and conditions. Others need planning permission or prior approval.
The rules depend on the property, the size and position of the extension, previous additions and whether any restrictions apply. Flats, maisonettes, listed buildings and homes in designated areas need particular care because normal householder permitted-development rules may not apply.
Bromley Council advises that building, extending or changing a property may require planning permission. Check the specific property and proposal before treating the work as permitted development.
Where certainty matters, your planning adviser can discuss whether a Lawful Development Certificate is appropriate. Do not rely on a neighbour’s project as proof that the same rules apply to your home.
3. Remember that planning and Building Regulations are separate
Planning permission and Building Regulations approval are not the same thing.
Even where an extension does not require a planning application, most extensions still need Building Regulations approval. The technical design may need to address structure, foundations, fire safety, insulation, ventilation, drainage, electrics, glazing and other matters.
Agree who will prepare the technical information, submit the application and deal with inspections. This should be clear before the contract is signed.
4. Check the Party Wall position
Building near a shared boundary, working on a party wall or excavating near a neighbour’s building can bring the Party Wall etc. Act 1996 into play.
The Government’s guidance says building owners must notify adjoining owners when proposed work is covered by the Act. A party wall surveyor can advise whether notices are required and help with the correct process.
Deal with this early. Leaving it until the planned start date can hold up the programme and strain relations with neighbours.
5. Build a proper budget
A usable project budget includes more than the builder’s main works.
Allow for the items that apply to your project, such as:
- architectural and technical design
- planning and Building Control fees
- structural engineering
- surveys and Party Wall advice
- utility alterations
- kitchen, bathroom and specialist finishes
- temporary accommodation or storage
- landscaping and making good
- VAT
- a sensible contingency
Ask for a clear written quotation with inclusions, exclusions and assumptions. If two quotes are far apart, compare the scope line by line rather than choosing the lowest headline figure.
6. Decide how the work will be managed
An extension usually involves several trades and a sequence of decisions. Before work starts, establish:
- who is responsible for day-to-day coordination
- who orders materials
- how changes will be priced and approved
- how often progress meetings will take place
- how payments relate to completed work
- who handles Building Control inspections
- what information the client must supply and by when
Clear responsibility is one of the best ways to prevent delays and misunderstandings.
7. Check the builder’s evidence
A professional presentation is not enough. Ask for evidence relevant to the type of extension you are planning.
Check:
- recent projects of a similar scale
- genuine client references
- current insurance
- a detailed written scope
- an achievable programme
- who will supervise the site
- how defects and snagging will be handled
- whether specialist work will be certified where required
Visit a completed project if that can be arranged. It is a practical way to judge finish, attention to detail and how the builder has dealt with the existing property.
8. Agree the paperwork before the start date
Do not wait until work is under way to settle the contract and payment arrangements.
The agreed documents should make clear:
- the scope and drawings
- the contract sum or pricing basis
- the payment schedule
- the start date and expected duration
- how variations are agreed
- client-supplied items
- responsibilities for permissions and inspections
- insurance requirements
- the completion and snagging process
For significant work, have the contract and any legal points checked by a suitably qualified professional.
9. Plan for living through the work
Extensions affect access, noise, dust, security and normal household routines. Ask the builder how the site will be separated from occupied areas and what facilities the team will need.
Confirm working hours, deliveries, skips, parking and how the property will be kept secure. If the kitchen or main bathroom will be out of use, agree the sequence and temporary arrangements before the job starts.
10. Choose a team that communicates clearly
Problems are easier to deal with when everyone knows what is happening. Look for a team that gives straight answers, records decisions and explains the effect of changes on cost and programme.
At Ryan & Sons Construction, we manage building projects across Bromley, North Kent and South East London. We coordinate the trades, programme and practical details from the early stages through to completion.
Planning an extension in Bromley? Contact Ryan & Sons to discuss the property, the work you have in mind and the next sensible step.
