Simply Loft’s Top Frequently Asked Questions

Frequently Asked Questions







Thinking of converting your loft but not sure how much you need to budget for, whether you need planning permission or even what a party wall agreement is? Simply Loft, your local London loft conversion specialist shares its most asked questions to provide advice on the process for converting your loft or attic space.


• How much does a loft conversion cost?
Most loft conversions will fit within the budget of £30K- £50K depending on the size and type. Don’t forget that at the same you may need to put some budget aside to cover extra items such as sanitary ware for an ensuite bathroom, flooring, built in wardrobes etc.

• How long does it take to build a loft conversion?
This really depends on the size and type of loft conversion you are intending on having. On average Simply Loft can build loft conversions in 8 weeks +/- 2 weeks. The fastest we can build a loft conversion in is 6 weeks.

• How do I know if I can convert my loft space?
As a rule of thumb you need 2.2m between the top of the floor joist of the loft to the bottom of the ridge beam. You can check your ridge height with a tape measure, which will give you an indication if the space is convertible. If your ridge height falls below this measurement, there are other ways to still convert your loft space, such as lowering the ceilings of the floor beneath your loft. The best way to know for certain is to invite one of our specialist surveyors to fully assess your property.

• What is a party wall agreement and do I need one?
A party wall agreement is required if your home has a wall that is connected to another property on either side. Each neighbour will have to be informed of the proposed works using a party wall notice form at least two calendar months before the intended start of the build. The party wall agreement is there to protect you and your neighbour from issues that might arise due to work done on the party wall. It draws up an agreement between you and you neighbour on what needs to happen if there is a problem. By law your neighbour can insist you have one before the work starts.

• What is permitted development?
If your property is not in a conservation area nor is a flat, you have permitted development rights (PD). This means you can develop your loft space without needing to gain planning permission. Your development will need to keep within the PD constraints i.e. terraced properties are allowed to develop an additional 40 Cubic Meters of extra space. Semi-detached and detached properties 50 Cubic Meters.

• What is the difference between permitted development and planning permission?
And will I need planning permission for my loft? Planning permission for loft conversions is usually required if your property is in a conservation area, is a flat or if you are working outside of the permitted development requirements outlined previously. With planning permission you are asking the council if your proposed scheme is acceptable. It is open to rejection by them and/or your neighbours and will have to follow the local development plan. Once the planning is submitted, it will take 8 weeks to hear the outcome. With permitted development you are asking the council to simply confirm that your scheme fits within the permitted development criteria. The council will issue you a Lawful Development Letter if they agree, which again takes 8 weeks. Technically you are not required to have the Lawful Development letter in place before the work starts and in fact there is no law stating you have to have it. This allows clients who request it, to start the work without waiting for the Lawful Development Letter thus saving time.

• How much disruption can I expect with a loft conversion?
Assuming we do not need to lower your ceilings, the disruption is kept to a minimum as the work is confined to the loft space and the heavy work can often be carried out from scaffolding outside your property. In fact a loft conversion can be considered as one of the least disruptive ways of extending your home.

• What are the different types of loft conversions I could have built onto my property?
There are many different types of conversions possible to a loft space including skylight, rear dormer, hip to gable or mansard loft conversions.


For descriptions of each of these types of loft conversions please visit

Not all of these conversions are feasible on every property so the best way of telling is to book a Simply Loft representative to visit your home.

Visit for more information.

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