The overall time taken to complete your cellar conversion is the total of the design/approval time and the building time. We have separated the two areas as some homeowners do not proceed immediately with the building works once the design and approvals stage has been completed. We have summarized the overall timings in a table at the end of each section.
Design/Approval Time
The day you decide to further investigate the possibility of converting your cellar, we will count as day 1 in the process.
The first step will normally be to speak to an architectural designer or a local builder to discuss your ideas and to find out if they can be done. Once an appointment has been made, there are a number of ways forward.
Some companies will do an instant property assessment on the day that you meet and provide you with sketch drawings and an idea of the cost of your proposal. At myhome mygarden, we prefer to complete our Feasibility Study in our design office as this gives us a better opportunity to assess the design in more detail.
Either way, we would advise that you allow 2-3 weeks for the initial feasibility/quotation process. You will then need to confirm that you wish to proceed with your project.
Your proposal may or may not require planning permission and this will affect the overall project time. For more information on whether or not planning is required, refer to our section on The Design Process.
Planning Permission Required
Once you have decided to proceed with your project, you should allow 2 weeks for the plans to be prepared and a further week for modifications that may arise.
If planning permission is required then it is normal practice for your designer or conservatory supplier to deal with the application for you, acting as your agent and you should allow a week for the application to be made.
Once your application has been made, it will generally take around 8-10 weeks to obtain a decision. For more information on this process refer to our Making a Planning Application factsheet.
Where a planning application is refused you have a right to appeal or to redesign it and resubmit it but this could add several months to the overall process.
Planning Permission Not Required
Where planning permission is not required, we would recommend that you obtain written confirmation of this from your local planning office as it may avoid any problems when you come to sell the property. (See our factsheet on Permitted Development.)
This will normally take 4-5 weeks to obtain.
Building Regulations/Party Wall/Quotations
You should allow 2 weeks for the building regulations plans to be prepared and, again, your architectural designer will normally submit these for you to the council. You should allow 4-6 weeks for them to be approved.
Some companies/designers will submit the building regulations application whilst planning is being considered (if required) to speed up the process but you run the risk that if planning is refused you will have to redesign the building regulations drawings.
You may also need to deal with other approvals required such as party wall issues (see our factsheet on The Party Wall Act for more information). This could add 4-6 weeks to the overall process.
Once all your approvals have been obtained, make sure that you have a final building quotation for the work and you are then ready to commence the building works themselves.
The table below summarizes the overall design time for a cellar conversion project.
| Task | Design Time Where Planning Permission is Required (weeks) | Design Time Where Planning Permission is Not Required (weeks) |
|---|---|---|
| Initial feasibility study/quotation | 2-3 | 2-3 |
| Finalise Design Scheme and prepare planning drawings | 2 | 0 |
| Submit planning drawings | 1 | 0 |
| Council deal with planning application | 8-10 | 0 |
| Prepare and submit building regulations application | 2-3 | 2-3 |
| Council deal with building regulations application, other approvals obtained and final quotations received | 4-5 | 4-5 |
| Total Design Time | 19-24 weeks | 8-11 weeks |
Building Time
The time taken to carry out the building work will clearly vary depending on the size and complexity of the project but also be aware that the following items will have an impact on the overall timing.
Pre-contract time
Before you give the go ahead for your project, check with your builder when he can start as you may not be prepared to wait if he is very busy. You may decide to use a different builder, even if they are more expensive, because they can start and complete the work sooner.
We would normally expect a period of 3-6 weeks from your confirmation for a builder to be able to start which will allow time to prepare any building contracts and sort out any final queries.
Weather
The weather conditions will clearly have an impact on the overall time taken to complete your building works. Certain activities such as bricklaying can not be completed in sub-zero or rainy conditions.
It may be worth considering erecting a temporary roof over the area of the work as this could save time although it will add cost to the project.
We would recommend that you keep a record of days lost due to bad weather and add these to the originally agreed completion date.
Builder's Work Method/Programme
Some builders are a lot bigger than others and can build several jobs at a time whilst some will complete one project before moving on to another. The amount of resources a builder has available to use on your project will have an impact on the contract time. If, for example, you have an average of 4 men a day on site, your project will be built faster than if you have 2. There will come a point where you can have too many people on site and different tradesmen will just get in each others way.
Whilst builders can be reluctant to provide you with a simple programme of works, we would recommend that you ask for one so that you have a good understanding of the planned method of carrying out the project and overall contract time.
The programme is a good method of monitoring the progress of the works and will highlight any key activities that you need to know about such as the staircase being fitted.
Time of Year/Working Hours
Whilst most builders normally work from 8 am until 4 pm, make sure you agree these before the works commence. Some builders may also like to work at the weekend but make sure any time restrictions are agreed as your neighbours may not be as happy as you are to hear the builders hammering away during their days off. Also be aware of any planning restrictions on working hours.
Building in the winter months may affect the overall contract time due to lack of light although the effect of this could be reduced by using temporary lighting.
Additional Work
Whether it is the discovery of unexpected additional work or you have asked the builder to carry out some extra items of work, this will normally add time to the overall project. It is unreasonable to expect the builder to complete the project to the original date where this occurs.
Where this does arise, always get your builder to give you a revised completion date.
At myhome mygarden, our project management system keeps track of time and costs and we will advise you of any change in these whilst the works are in progress.
Disputes
Whilst it is hoped that any disputes could be avoided by entering into a clearly defined, written agreement with your builder, sometimes they are unavoidable. The majority will result from either your own or the builders expectation being different from the reality of the situation.
You may not be happy with the standard of workmanship and want an item rectifying before works proceed any further. The builder may have purchased completely the wrong type of floor tile. You may not have paid the builder on time because the bank has messed up a money transfer.
Whatever the dispute is about, it is in all parties’ interests to resolve it quickly and we would always recommend a face to face meeting. Where it is not possible to resolve, it is good practice to have agreed a method of resolving disputes before works commence.
At myhome mygarden, we pay particular attention to the drawings and specification at the design stage in order to reduce the chances of any disputes at the building stage.
Late Delivery
Sometimes there may be delays in the manufacture and delivery of the frame, glass or roof components. The programme of works is particularly useful for determining when these items will be required on site.
Business Failure
Quite clearly, if your builder goes out of business during the building process, the works will be delayed. However, also be aware that the same effect can be caused by his suppliers or sub-contractors ceasing trading.
There isn't much you can do to avoid this but we would advise that you protect your position by checking the builders credit rating and making sure you are only paying for work that has been completed.
The myhome mygarden project management system does provide protection against this as your contract for the building work is with us so if a builder does cease trading, we will arrange for another contractor to complete the works.
Summary
Whilst many of the above items could cause delays to your project, a well thought out and detailed project will minimize the risk. We would advise the following contract period for the conservatories shown.
| Extension Type | Build Time |
|---|---|
| Small/Medium Cellar | 8-10 weeks |
| Large or Extended Cellar | 10-15 weeks |
For a more detailed look at how garages are converted. refer to our section on The Building Process.
Overall Project Timing
In the table below, we have added the design time to the building time to show an overall 'project time'.
| Task | Overall Project Time Where Planning Permission is Required (weeks) | Overall Project Time Where Planning Permission is Not Required (weeks) |
|---|---|---|
| Total design time | 19-24 | 8-11 |
| Pre contract time | 3-6 | 3-6 |
| Building time | 8-15 | 8-15 |
| Total Project Time | 30-45 weeks | 19-32 weeks |
From the above summary you can see that, if you are thinking of converting your cellar, be realistic about the overall timing, particularly the design and approval time which often takes longer than the actual building time. If possible, try and get your plans completed and approved well in advance of the building work.
How can we help?
myhome mygarden can provide a comprehensive Feasibility Study for any cellar conversion project that you are considering which is an excellent way of finding out long a specific proposal will take. See the Feasibility Study section of our site for more information.
If you decide to use myhome mygarden for your cellar conversion project, our Project Management system is set up to tightly control the overall time our approved contractors take to complete your works.
Call us Free on 0800 3800 141 to find out more.