How Long?

Do you have a home extension in mind? Alongside the budget and the ideas, the timeline is one of the most important considerations. Many factors influence the length of a project and the factor clients tend to worry about the most is planning permission. One of the most common questions the team at Nett Assets are asked is, ‘How long does the planning application take?’

Do you have a home extension in mind? Alongside the budget and the ideas, the timeline is one of the most important considerations. Many factors influence the length of a project and the factor clients tend to worry about the most is planning permission. One of the most common questions the team at 50 Degrees North are asked is, ‘How long does a planning application take?’

We break down some of the factors that influence the timeline for applying for planning permission. It also highlights other key elements that impact timing, which you may not have thought of.


Client-imposed variables

Time is a critical factor when it comes to home extension projects. From your side, there are certain things that affect the project timeline. Think about whether you have any particular time constraints. Ask yourself the following questions:

When would you like Work to start?

Do you have a particular start date in mind – for the building works or the project generally? Sometimes this is influenced by family needs, a baby’s due date, or having work done within a certain financial year.

Are there any hard stop dates? This might be because you’re starting a new job, or you have a child starting school.

The stages of a residential extension

Stage 1: Preparation

Ahead of the build, there is a lot of preparation to be done. At this stage we will: carry out site surveys; draw existing plans, sections and elevations; develop the brief with the client; draw proposals and issue revisions; meet and develop the design and discuss the next stages.

Stage 2: The Planning Application

This is when your architect will: prepare the drawings for planning submission; prepare planning documents; commissions any consultants if required; liaises with the planning department and makes changes if requested; advises client on progress.

Stage 3: Building Regulations and Tendering Work

At this stage in the process your architect will: meet with you and discuss detailed design; commission an engineer; commission sub-consultants; draw and issue Building Control level drawings, spec and SOW; facilitate tender discussions/provide builder shortlist; issue tender information.

Stage 4: The Building Stage

This is where the project starts to take physical shape. At this point your architect will: hold a pre-start meeting on-site if required; carry out site meetings; develop details; draw interior elements; liaise with your builder; solve problems & ensure Building Control sign off.

Underlining the entire process, there’s the time-cost-quality triangle to consider. If you have a particular quality of build in mind, or a particular budget, it can effect the timeline adversely.

For instance, you might choose a builder for the quality of their work; a high-quality finish isn’t cheap and may not be the fastest option if speed is your main concern. You might choose a builder because you’re familiar with them, though maybe they are not available when you would like. Again, this will impact on the overall timeline.


No matter what the project, our advice is to never, ever rush to site. It’s better to take your time. Do things thoroughly in the beginning and there’s less chance of running into problems down the line.

We understand it’s frustrating! We’ve been involved in hundreds of these projects and we know that it’s tempting to get stuck in straight away. In our experience, it’s much better to spend time in the preparation than in the fixing of problems caused by premature arrival on site.


The size and complexity of the project will impact timelines as well as the building works. Below we’ve outlined typical timelines for each kind of project. These are a guide only; your architect can discuss the finer details with you.

Be aware that these timelines refer to the length of time to getting on-site. They do not include building timelines:

Typical residential extension or refurb – five to six months

Larger residential extension or refurb – from six to nine months

A complex project, involving basements or a back-to-brick refurb – 6 to 12 months before getting on-site. New build – up to a year to get on site.

How will my architect help manage timings?

Your architect will help you define a brief. They’ll go through the scope and feasibility of the work. Essentially, your architect will help you get these things right at the start, to reduce the risk of wasting time once you get onto site.

Practicality vs. inspiration: the architect’s role

Whether they’re guiding you through different options or giving you the lowdown on timelines, our  job is to balance the practicalities with the inspiration.

We will help you to pin down everything from your initial ideas to your budget, in order to define a brief. All of these contributing factors add up to a timeline. There’s a saying that money is the most used building material. The same could be said for time! Through their knowledge, skill and pragmatism an architect helps keep the project on the straight and narrow, while upholding your vision.


The short answer is, no. Even with the most meticulous planning, once you arrive on-site, all kinds of unforeseen things can crop up. A good architect will prepare you for the worst. Of course, they hope it doesn’t happen, although it’s good to be aware of the implications in case it does.

It’s why we at Nett Assets believe that it’s better to plan and prepare beforehand so that you can make effective decisions. You’ll feel equipped to deal with what’s possibly going to come up thanks to our thorough approach. If you rush on to site, it’s usually a case of learning through a baptism of fire. Of course, nobody can eliminate every unforeseen circumstance – either at the planning or the building stage. Being aware of these things makes them easier to deal with.

Make a start on your home extension or renovation project, contact us for an initial conversation. We might not be able to give you an accurate timeline immediately. We can promise that we’ll listen to your goals, your vision and support you as you bring your dream to life.

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