The Potential Pitfalls of Replacement Conservatory Solid Roofs, PLUS Ensuring Any New/Replacement Conservatory/Orangery Complies with both the Building Regulations and Planning Law

When it comes to adding a conservatory or orangery to a dwelling or changing a glass roof for a solid one, many UK home owners have sadly been badly advised by misinformed neighbours, double glazing suppliers and double glazing salesmen looking for a quick sale without advising you of the serious consequences.

This has led to expensive and time consuming non-certain of success retrospective planning applications and/or Building Regulations applications having to be made, and in many instances planning enforcement notices then being issued to take down structures erected illegally, where neither the home owner or installer had sought the necessary legal approvals before extending or altering the current dwelling.

That said, you can of course have the conservatory, or orangery or extension of your dreams as long as you have first sought and obtained all the necessary permissions before commencing work.

Some glass extensions do need both planning permission and Building Regulatory Approval, whilst some need full planning permission only, or to apply for and comply with the Building Regulations. When it comes to replacing a translucent conservatory roof with a solid roof, most conservatory owners don’t realise that they can only do so by first obtaining Building Regulatory Approval, as by changing from say a glass roof to a solid insulated one, the classification of the structure changes from a temporary structure to a permanent one, and in many cases will also now need planning permission due to the “change of use”.

If the existing conservatory with a translucent roof was built with planning approval, it is 100% certain that 1) a new planning application will be needed due to “change of use” (please note there is no certainty of approval) and 2) a full Building Regulations application will also be required.

It may be helpful to first know what the “official” definition of a conservatory or glass extension is. Conservatories, porches and other such glass extensions share a common description with Regulation 9(1), 21(4) stating to meet the exemption status in Schedule 2 Class 7 of the Building Regulations.

• They must be at ground level and be less than 30 square metres.

• They must be thermally separated from the dwelling by walls, windows or doors which meet the energy efficiency requirements (or retain the existing doors).

• The dwelling’s heating system must not be extended into the conservatory, orangery or porch. Heating should either be completely independent of the dwelling or be provided with effective controls to operate and isolate the heating from the dwelling.

A conservatory or any other type of glass extension must have a significant proportion of the roof (75%) and walls (50%) glazed to be considered exempt from having to apply and comply with the England and Wales Building Regulations. Consequently by adding a solid rood the structure then becomes a de facto extension with all that entails.

Your local Building Control Officer may require the new structure to have roof vents, and/or trickle vents retrospectively fitted to windows, or other changes made to the existing structure. There will certainly need to be adequate ventilation. Even if the actual new solid roof system has building regulation approval as a product that will comply, the remainder of each structure may also need to comply, and may need “Change of Use” planning permission as the structure is changing from a conservatory to an extension. In some cases property owners may unwittingly be exceeding any intact Permitted Development Rights if the floor area of the conservatory is greater than PD rights allow. If since the conservatory was built the Permitted Development Rights have been withdrawn by the local authority, then it will not be possible to add a solid roof without first obtaining planning permission.

The existing roof will either be glazed or polycarbonate and most typically here in the UK will have UPVC window and doors. If the roof is glazed, it is likely the vertical frames will have been designed to carry the roof load. In the case of a polycarbonate roof, the vertical frames may only have sufficient reinforcement to carry that particular load.

If there is insufficient reinforcement (which is usually the case) new window and door frames will be needed to support the weight of the roof. Several “new” replacement solid roofs have already collapsed due to insufficient load bearing, poor design and lack of structural calculations undertaken by installers.

The existing foundations should have trial holes excavated to ensure they are adequate to support the new loading.

According to the Local Authorities Building Control guidance on adding a solid roof, “your local authority building control team is likely to ensure that the roof and supporting structure fully complies with the Building Regulations.”

So before ordering a solid roof for an existing conservatory or a new structure that has a solid roof, make sure the necessary planning permission and Building Regulatory Approval is obtained before money changes hands and work starts.

If you’d like free expert advice from one of Hazlemere Windows experienced expert conservatory design consultants they will be able to offer you a no obligation site consultation.


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