A single storey rear extension can fall under permitted development, meaning planning permission may not be required providing it meets certain criteria.  

In terms of height, the extension must:

• Be no taller than four metres at its highest point

• Have eaves no higher than the eaves of the original house

• Not exceed the height of the original dwelling  

Read about planning permission for extensions on Planning Portal

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Creating a new basement will usually require planning permission, particularly if it affects the external appearance of the property. For example, installing a lightwell to bring natural light into the basement may be subject to stricter design rules if it is visible from the street, especially at the front of the property, compared to those at the rear or side.

Because basement construction involves significant excavation and structural work, permission is often necessary. It’s recommended that you consult your local planning authority early on to understand what is likely to be considered acceptable before submitting a planning application. Building regulations will also apply to a new or conversion of a basement.

Read further guidance on basements.

Inefficient windows and doors can significantly contribute to heat loss. Replacing single glazed windows by installing double glazing can cut heat loss through windows considerably. Double glazing works by trapping air between two panes of glass creating an insulating barrier that reduces heat loss, noise and condensation.  

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If you can't replace all the windows, why not choose the rooms that cost you the most to heat? Other options to reduce heat loss through windows include sealing gaps or using thermal blinds.

You don’t usually need planning permission for repairs, maintenance and minor improvements or replacing windows and doors that are of a similar appearance.

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Building regulations apply to replacement glazing, in terms of thermal performance, air supply, ventilation, safety and means of escape.

Read about planning and building rules for doors and windows

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If you plan to put up a small, detached building like a garden shed, garden room, garden office, annexe or summerhouse (all classed as outbuildings), building regulations generally won’t apply if the building has a floor area under 15 square metres and does not include any sleeping accommodation.

For buildings with a floor area between 15 and 30 square metres, building regulations approval is usually not needed - as long as the building does not include sleeping accommodation and either:

• it is at least one metre away from any boundary, or
• it is built mainly from non-combustible materials.

Read more about the building regulations that apply to outbuildings.

Don't forget to check the permitted development rights for outbuildings.

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Planning permission is not normally required for steps in a garden, however, permission may be required if the steps are part of a larger project such as a raised deck attached to the front of the house.

If the external steps are attached to the house and a roof is constructed, this will become a porch which has different rules attached. Read full details on the planning rules for porches in our common projects section.

Different rules may apply if you live in a designated area such as a conservation area or if the building you live in is listed.

External steps will not normally require building regulations approval unless they are part of the access to the building. If they are then you must ensure that you do not reduce the level of accessibility to the house.

You should contact your local planning authority for further project advice, alternatively, you can apply for a lawful development certificate for confirmation that any changes you make do not require planning permission.