Guide to Attic Conversions
An attic conversion can be a great way to add space to your home especially if you don’t want to lose space in your garden. However, there are a few things that need to be considered early in the planning stage to decide if an attic conversion is suitable for your home.
- Roof Height
Not all attics are suitable for conversion, the first thing to check is whether you have sufficient height. Part F of the Irish Building Regulations states that you must have a minimum ceiling height of 2.4m for 50% of the floor area which is above 1.5m high. If you don’t meet these regulations but you have sufficient height to stand up and walk around comfortably, you may still convert your attic however, it can only be used as storage space.
It is important to consider how you will gain access to the attic. In some cases the new stairs may take up almost as much space as you are going to gain. A spiral stairs will normally use the least amount of space.
It is advisable to use a Structural Engineer when making any alterations to your roof structure. Sometimes it is necessary to remove or relocate collar timbers or struts, it is important to get an engineer to do the necessary calculations and specify alternative means of supporting your roof before doing so. Your attic floor structure normally needs to be strengthened also by increasing the size of the floor joists, remember this when checking that you have sufficient ceiling height.
Natural light is important in every space in your home. There are many different ways of getting good quality natural light into your attic rooms. There are various different types of rooflights, ridge rooflight systems, frameless rooflights, balcony rooflight systems, etc. These can be manually or electrically opened to give you natural ventilation as well as light. Dormer windows are also a great way of getting light into your conversion with the added benefit of additional floor space.
Planning permission is required for any chances to front or side of your house. You may add Velux roof lights to the rear of your house without needing planning permission. Dormers and balconies would require planning permission. Protected structures always require planning permission.
- Fire Safety
If you are converting the attic in an existing two storey house then the attic conversion would result in your house becoming a three storey building meaning that there are a number of Fire Safety regulations which you will need to comply with. These include but are not limited to creating a fire protected stairway including upgrading some of your doors to self-closing fire doors, each new attic room to have a window or roof light for escape or rescue.
Part B of the Building Regulations sets out mandatory fire safety requirements; and Technical Guidance Document B (TGD-B) shows how to comply with Part B.
In most situations the roof of a house is insulated at ceiling level, which is your attic floor. Now that you are going to use this space, the roof must be insulated at rafter level. The existing insulation is usually fibreglass quilt insulation, this can be left where it is as it will also help slow the heat escaping from the rooms below and act as sound proofing. The new insulation at rafter level must comply with Part L of the Irish Building Regulations.
For more guidelines on converting your attic please check this publication from the Department of Environment, Heritage and Local Government: