How long does a kitchen extension take? I’m an experienced renovator and this is how long I’d allow

We all dream about the tweaks and changes we would make to create more space in our homes, especially when it comes to making the kitchen bigger. But how do you practically make this reality and how long does a kitchen extension take?

Planning a kitchen extension is complex; from setting out a budget and pulling together your kitchen extension ideas to finding a contractor and laying out a schedule of works.

With my experience as a renovator, and with the advice of kitchen extension experts, this is how long you can expect your kitchen extension to take, the schedule of works that I'd follow to get it done on time, and the factors to be aware of that will slow your project down.

How long does a kitchen extension take?

A kitchen extension timeline is generally split into two timelines. The design phase and the build phase. The design phase can take around six months and includes finding and working with an architect or a designer, as well as applying for any relevant planning permissions. The build phase can take at least the same again.

Yaniv Peer, director at Iguana Architects advises: 'On average a kitchen extension takes 18 months from start to finish.'

'I would say it largely depends on the level of ambition, overall size and how much other refurb work might be going on in the rest of the house,' adds Mike Bell, founder of FAB Architects.

'However there are some baselines that are common to all projects. Following the RIBA stages [the design process for certified architects] there are a lot of important steps to get right before you even get to site that can be quite time consuming, especially if the planning process is drawn out.'

When all of this is done and dusted, the build phase will start with groundworks and demolition, before the foundations and new structure can be erected.

'Realistically, based on projects we have worked on and been exposed to, I would say to expect up to 6 months before breaking ground and then at least 6 - 12 months to completion,' continues Mike Bell.

'I would also note to clients to be aware that contractors will often try and convince clients that it will take less time than reality often in a bid to win work. So be careful when a contractor provides a timeline that seems too good to be true.'

Knowing how long the process will take might also impact when you should extend your kitchen; starting in the winter to get the design and planning stages out of the way before breaking ground in summer is a popular route for many.

Mike Bell

RIBA-certified Mike Bell founded his Sussex-based practice in 2017, focussing on sustainable design solution for homes across the South East of England.

What’s a typical schedule of works when it comes to a kitchen extension?

A typical schedule of works will go as follows:

Design phase (six months)

• Brief the architect
• Concept plan review and amendments
• Sign off on design
• Apply for planning permission (if required)
• Submit building regulations application
• Finalise necessary admin (party wall agreements/home insurance)
• Hire a project manager or find a good builder and organise trades personally by comparing quotes

Build phase (six-12 months)

• Clear the site
• Groundworks and foundations
• Erection of structure
• Get to weathertight stage
• First fix (electrics, plumbing etc.)
• Second fix (flooring, plastering, making good etc.)
• Install kitchen and decorate
• Snagging

What factors can influence how long it takes to extend a kitchen?

Unfortunately, all great plans can be delayed and derailed, and this can be down to various factors.

• The design phase itself might be slowed by choosing the wrong architect for the job — your own ambitions might not quite align with theirs.
• A frequent bottle neck for many extensions is also obtaining planning permission. If your design doesn’t comply with permitted development or you live in a Listed Building or Conservation Area, you will need to submit a full planning application. Generally they say this will take around eight weeks, but it can drag out for an indefinite amount of time, especially if your local authority is experiencing a backlog.
• During the build, last-minute changes to the design will extend the process (and add to costs), so it is always best to stick to what was agreed during the design phase.
• Availability of materials and labour is also a sticking point for many. Good builders get booked up months if not years in advance and a conflict between supply and demand of essentials, such as plasterboard as in the Covid lockdown, will delay the process.

'Having as much of the information prepared and decisions made ahead of starting on site will really help keep things on track and avoiding situations where clients are responsible for ordering items to fit in with the contractor's schedule helps,' adds Mike Bell.

'When clients insist on organising their own trades to go in and gel with another team, this often leads to a delay in our experience and can wipe out the cost benefits.' Find out if you should save costs going this route or if it's best left to the professionals with our guide to project managing an extension.

How can you help keep your kitchen extension on track?

'Delays in a project can be classified as controllable and non-controllable, ' comments Yaniv Peer. 'Controllable delays often arise when project details, such as interior elements, are not fully specified, causing the contractor to wait for decisions. Additionally, selecting an unsuitable contractor or design team can lead to delays in providing necessary information, poor site coordination, and issues that prevent alignment with the project schedule.

'Non-controllable delays include supplier setbacks or financial collapse, as well as external factors like global pandemics and extreme weather. For instance, concrete cannot be poured in extremely cold conditions, and excessive rain can prevent mortar from drying properly, particularly during below-ground construction.'

The top ways to keep a kitchen extension moving along at a good pace would be to:

• Use an architect and pay them to assist applications for planning permission. They know the industry and expectations of your area better and will achieve results at a quicker pace.
• If you’re project managing the build phase, ensure you have all trades lined up with a realistic timeline. Keep everyone in the loop about delays. Hiring a project manager will further speed up this process.
• Move out of the house before groundworks begin. Builders working around you and having to ensure a constant supply of hot water and power can slow down progress.
• Don’t make changes to the plan once the build phase has begun.
• Have a contingency budget set aside so you can quickly react to price hikes or issues along with way.

Yaniv Peer

Yaniv Peer founded Iguana Architects in 2017, specialising in green urban developments and residential projects.

FAQs

Can you live in the house while the kitchen is being extended?

Absolutely you can live on site in a house while it is undergoing a renovation or extension. But you have to be prepared for discomfort and mess.

To prepare, ensure you will have at least a sitting and sleeping area that will be unaffected by the works. Setting up a temporary kitchen is hugely advisable as you will be without a sink, oven and storage for at least a couple of weeks.

'Clients living off site helps the contractors make progress fast without clients looking over their shoulder,' explains Mike Bell.

'If you do go down this route it's important to book in regular inspections where progress can be discussed with the contractor, as a client and with your architect. This is something you miss from being directly attached to the work that is being carried out. The work we carry out I would say is probably 75% families staying in the house and 25% families moving out. The projects where people move out do seem to go smoother.'

During my own renovation we had to wash plates and pots in the bath and there was dust everywhere. Everywhere. No matter how often you clean and how much you cordon off rooms.

Despite the negatives, it’s a very good way of saving money if you don’t have nearby relatives or friends to move in with. It’s also a bit of a novelty of feeling like you’re really ‘in’ the extension process. But it is not for the faint hearted and you will need to compromise on many home comforts.

If you have an attached garage next to your current kitchen, then a garage conversion could be a simpler and quicker way to get the extra kitchen space you are after.

Are you planning on extending your kitchen? Let us know all about it in the comments below.