No, it would almost certainly not be ok to build a conservatory on land that a covenant reserves for gardening.
But that doesn’t necessarily mean that your mother may not be able to have her conservatory.
Covenant Law – A True Minefield
The first thing to point out here is that this advice has to be general because we don’t have access to the covenant, your mother’s plans or the local plans for the area. Also covenants are a real minefield so you need to take advice from a specialist conveyance solicitor or a solicitor who specialises specifically in covenants. But there are a number of different avenues that you can go down.
The first thing is that covenants can be lifted. Generally a restrictive covenant on a residential piece of land would have been placed there so that the buyer of the land would be prevented from doing something that the seller didn’t want them to do (building a conservatory for example!).
Lifting a Residential Development Covenant
It’s likely that an application to lift a covenant of this type can be dealt with by the local or county council, but a solicitor would need to look at the covenant to decide that. If it is, then make the application and then the covenant will be lifted unless anyone objects.
Objections can come from the person who placed the covenant, neighbours, or members of council offices if they felt that lifting the covenant would go against local planning guidelines or rules.
Dealing with Objections
It could be that the person who placed the covenant is no longer living or cannot be contacted, and no neighbours object, and a conservatory is acceptable to the planners, then the application to have it lifted should be accepted.
If someone objects then try to discover the basis of their objection. If they don’t like your mother’s plans then perhaps they can be changed to get round the objection and then an application to lift the covenant can be put back in again.
Look for Loopholes in the Covenant
An alternative is to have the covenant examined by a specialist covenant solicitor. Many covenants haven’t been drawn up correctly and if that’s the case a specialist may find a loophole that makes the covenant unenforceable.
There is a good chance that your mother can get her conservatory but you must seek specialist advice before you begin building.