ATTIC/LOFT CONVERSION
One of the most attractive home upgrades in the UK to expand current space is an Attic/Loft This particularly well suited to properties where double story house extensions are not feasible.
The average costs for Attic/Loft conversions range somewhere between £15000 – £55000. These conversions range from single room, dormers, premanufactured off-site dormer to be installed by crane etc.
Adding a single room or toilet in a typical house can increase the value of the property by 20%,
Most Attic/loft conversions fall into permitted development which means that planning permission is not required. Planning permission may be required if you stay/reside in a listed building or a designated area. Building regulations will also need to be followed.
The most important consideration for an Attic/Loft conversion is the existing roof structure and the requirement for access for example stairs, risers etc. Ventilation, heating and light will also need to be considered.
TYPES AND COST OF ATTIC/LOFT CONVERSIONS
1- Room Conversion
One of the simplest and feasible conversion that could be done room loft conversion. This typically costs around £15000 and is the cheapest and most simple option. A room conversion typically involves and may or may not be valid to every conversion:
- Strengthening the floor
- Velux windows, skylights
- Addition to insulation
- Stairs for access
- Heating, lighting and electrics
- Fire safety adhering to Building Regulations
2- Dormer Conversion
Where rooms are formed at the attic level with addition of new walls, windows, new roofing elements is called a Dormer conversion This type of conversion usually costs £20,000 and up to £35,000 to £45,000 for a double room and ensuite.
3- Roof structure change
This type of conversion is the most expensive and complex and requires hiring a designer and to apply for planning permission. This conversion which usually cost £40,000 and above. In this conversion premanufactured structure would be craned into position and a new type of roof would be required such as hip to gable.
IS PLANNING PERMISSION REQUIRED
?
Planning permission for most simple conversions are not required as they are treated as permitted development. Even though planning permission is not required design of the conversion must follow the specified requirements.
Planning permission is required in the case where the conversions lies out with the requirements of a permitted development, or if the property is located in a conversation area, If the roof is being altered in any way, or if the building is listed.
Lead Structural LTD, can help you in obtaining planning permission.
BUILDING REGULATIONS
Building Regulations approval must be required when any attic/loft conversion is taking place. A building control surveyor will need to visit and inspect the conversion at various stages and will provide a completion certificate. If your property is semi-detached or terraced, then the neighbours must be notified of the planned works this falls under the party wall act.
Attic/Loft conversions fall under parts B, K, L and P within the Building Regulations
Part L of the Building Regulations requires U-value targets for thermal efficiency to be met once you convert your loft into habitable space.
Part K concerns preventative measures from falling, collisions and impact, and requires a minimum headroom of 2m for all escape routes, including the steps (although the principles are relaxed a touch for staircases providing access to a loft conversion).
Parts B and P are concerned with fire and electrical safety respectively. Complying with Building Regs’ requirements fire safety is often complex. In two or more storey homes, where an escape window would be quite 4.5m from the bottom level, a ‘protected’ staircase must lead right down to an outside door — which may cause some issues if your staircase rises from an area , instead of the hallway on the bottom floor, or your ground floor is open plan. There are typically solutions in both instances, but this area needs consideration together with your design and/or build team.
CAN MY ATTIC/LOFT BE CONVERTED
The eligibility factors for the conversion include multiple factors:
- Internal Height:
Required usable space of 2.2m is required for the suitability of the conversion this should be measured from the bottom of the ridge to the top of the ceiling tie. As there is no building regulations extent on minimum ceiling height for habitable rooms a 2m height is required for stairs which could be taken down to 1.8m on the edge of the stairs. In case of height less than 2.2m two options can be considered (but be aware these are costly options)
Option1: Increasing Roof height
This is structurally feasible, but the main problems are the high cost and getting planning permission approval. If the entire roof area needs removing, a covered scaffold structure, to guard the house from the weather during the works, would even be
Option 2: Decrease Ceiling Height
This will require all the presentceilings in question to be removed, causing much mess. With this method a plate will be needed to be bolted to the wall using shield anchors or rawlbolts, for the new floor joists to hang from. there’s also a requirement for an appropriate tie between the roof structure and therefore the dwarf wall formed, to stop the roof spreading.
You will even have to assess whether the space you’re gaining within the loft makes up for the space you’re losing within the rooms below.
- Pitch of the Roof
Suitable internal height also means suitable roof pitch, In the event that dormers are required then the pitch of the new structure could be made to suit the required the height.
- Structure of the Roof
Typical timber trussed structures are the most suitable type for conversions. This is inexpensive when compared to other roofing materials. The rafters, ceiling ties may need to be strengthened to adhere to the new loads. Trussed roof requires more structural input but this is easily rectified by using steel beams and bearing supports for the ridge.
- Obstructions such as chimneys, water tanks etc
Mostly all obstructions will need to be moved to a different location. In case space for water tanks etc is not sufficient then a different water system may need to be provided.
DO I REQUIRE PROFESSIONAL HELP
?
Even though the Attic/Loft conversion could be designed yourself, it is recommended to appoint and architect or designer.
Architect / Structural Engineer
This route will help you to design your conversion to your specifications, the design fees are something to be considered in this option. The architect / structural engineer would also help in obtaining the required planning permission etc.
Lead Structural LTD can provide you a cost-effective solution as all architectural and structural work is done in house.
STAIRCASE REQUIREMENTS
The perfect area for a staircase to land is in accordance with the rooftop edge: this will utilize the accessible height over the staircase.
The minimum height required over the pitch line is 2m, although this could be decreased to 1.9m in the middle, and 1.8m to the edge of a stair.
The real position will rely on the layout of the floor underneath, and where required the accessible height can be accomplished utilizing a dormer or including a rooflight over the staircase or, if suitable, changing over a hipped roof end to a gable.
- Maximum steps in a straight line are 16
- Step size: Maximum height of each step is 220mm, length is at least 220mm; these estimations are taken from the pitch point. The step has a nose that protrudes 16-20mm before the pitch line. The proportion of size must not surpass the greatest edge of pitch requirement of 42°. Any winders must have at least 50mm at the tightest point. The width of steps is unregulated; however, the winders are probably going to confine the decrease in width.
- Balustrading: The height at least is 900mm over the pitch line, and any spindles must have a separation in between that a 100mm sphere cannot pass through.
Lead Structural LTD, can provide competitive prices for the design, drawings and specification for all stair types.
WILL MY CEILING JOISTS BE REPLACED
?
In most cases ceiling joists need to be strengthened to allow the extra load due to the habitable space.
Lead Structural LTD, can provide cost effective solutions for strengthening the ceiling ties.
LIGHTING, INSULATION AND HEATING
The most important factors for any conversion are either bringing natural light in the conversion by use of Velux windows, roof lights etc. Providing artificial lighting such as down lights, track lighting etc. Heating the conversion by providing Insulation dependant on cold or warm roof methods, Insulating the floor, Insulating the party walls.
Lead Structural LTD, can provide full architectural services which include all lighting, insulating elements we can also provide you with accurate 3D models showing all the above as per your requirements.
Bathrooms in Conversions
Adding a bathroom depends on the location of the existing services. Hot or cold water supplies can be simply be provided by branching off the existing plumbing system.
FIRE SAFETY AND REGULATIONS
Fire safety regulations can easily be followed as per Building Regulations B and P,
- For Single Storey:
- Egress window openings are needed to serve all first floor habitable rooms but not bathrooms.
- Openings should be atleast 450mm x 450mm and minimum of 0.33 sqr metres
- Rooflights usually be top opening bottom of the opening to be between 800mm and 1100mm from the floor.
- For Two Storey:
- Escape windows that are over 4.5m from ground level are not viable. Instead, the Building Regs require a protected stair enclosure that leads right down to the final exterior door
- If your staircase rises from a room, rather than a hall, you have two choices:
- It can be entirely enclosed within a hallway to an external door
- The staircase can be enclosed in a lobby at the base of the stairs. The lobby will have two separate doors, to offer a choice of either a front or back route of escape. These doors and the lobby walls will need to be fire-resistant and most likely open outwards into the rooms to avoid fouling the bottom of the stairs. If the doors do not open outwards into the rooms, they will be acceptable as long as they create viable options for escape in the event of a ground floor fire
- For open plan homes, where the staircase lands in an open plan space, a sprinkler system may be the only option.
- Floor Joists
A minimum of 30 minutes fire protection is required. - Doors
Fire door are required at the top or bottom of new stairs, Existing doors on the stairway may also provide a minimum of 20 minutes fire protection. They cannot be glazed unless fire rated glass - Smoke Alarms
Mains powered smoke alarms are required at each floor of the house, Wireless alarms can also be fitted.