Helpful Building Advice for DIY Conservatories
Building regulations will generally apply if you want to build an extension to your home.
However, conservatories are normally exempt when they meet a number of conditions:
- They are built at ground level and are less than 30 square metres in floor area.
- At least half of the new wall and three quarters of the roof is either glazed or translucent material.
- The conservatory is separated from the house by external quality door(s).
- Glazing and any fixed electrical installations comply with the applicable building regulations requirements (see below).
You are advised not to construct conservatories where they will restrict ladder access to windows serving rooms in roof or loft conversions, particularly if any of the windows are intended to help escape or rescue if there is a fire.
Any new structural opening between the conservatory and the existing house will require building regulations approval, even if the conservatory itself is an exempt structure.
Always check current building regulations and requirements with your local authority.
If Conservatory Building Regulation Consent is required, what conservatory building regulations apply?
Energy Conservation Conservatory Building Regulations
The most frequent situation where conservatory building regulations apply and approval is required is shown in the pictures below. With a design like this, the “conservatory” is not removed from the home and under the conservatory building regulations; this has to be regarded as an extension.
The UK Government is committed to reducing energy usage and carbon emissions from UK power stations. In light of this Conservatory Building Regulations now include set levels of the volume and varieties of glazing in conservatory extensions (and new homes).
To meet the Conservatory Building Regulations, in this case, there are options:
- Provide the local building control department with calculations showing the level of glazing in the conservatory/extension, also showing the level of glazing in the windows, doors and roof lights (if applicable) in the original home does not exceed 25% of the floor area of the conservatory and all floors of the home combined. The new doors and windows in the extension/conservatory will need to adhere to the current U values. Types of glazing which will meet this criterion are given in the table below.
- Provide Building Control with calculations or blueprints that show the volume of glazing in the windows, doors and roof in the conservatory/extension does not exceed 25% of the total floor area of the conservatory/extension. The new doors and windows in the extension/conservatory will need to adhere to the current U values. Types of glazing which will meet this criterion are given in the table below.
Examples Of Types of Glazing That Meet Current U Values
Building Regulation consent will always be required where it is necessary to form a new or wider opening in the original house wall (see Example 2). This is because, carrying out this type of work is a structural alteration. Your local building control department have to examine the supporting beam or lintel to confirm if it is of suitable size and fire proof.
Irrespective of whether your conservatory is exempt, glazing in some of the windows and doors requires them to be either strengthened or laminated safety glass so that they meet British Standard BSEN12600. Normally, the areas, which need safety glass, are doors and side panels, also where the glass in windows is within 800mm of floor level.
When a “Conservatory” is considered by law to be an extension, as well as energy conservation, there are additional building regulations, which will also apply. These include the following:
- Foundation designs. (Raft foundations may not be suitable – check with your local building control department).
- Fire spread across the boundary. (Large amounts of glazing are not allowed on or near to the boundary – check with your local building control department).
- Preventing damp. (floors with damp proof membranes and cavity walls with damp proof courses).
- Drainage (Surface water from gutters and down pipes need to be discharged to a proper drain and not simply into a rainwater butt).
- Ventilation of adjacent rooms. (Example 2 shows the Dining Room window enclosed. In order to adhere to building regulations it is believed that the dining room and living room/lounge would need to be merged into one room (open plan) with ventilation being provided by the Living Room/lounge window).
For an exempt Conservatory, energy savings can be achieved in the following manner:
- Installing energy efficient lamp-holders which can use compact fluorescent bulbs.
- Installing an independent thermostat in the Conservatory to control levels of energy consumption should fixed radiators/heaters be fitted.
- Installing independent on/off switches/isolators to radiators/heaters to guarantee that energy is not exhausted when the conservatory is not in use during the winter months.
These notes are for your guidance and information only. For the avoidance of doubt please contact your local planning and building regulations authority before undertaking any work.