“Over the next five years the National Trust aims to renovate more than 5,000 buildings to meet a set of minimum environmental standards that include installing maximum loft insulation, water saving devices, rainwater storage, double or secondary glazing, thermostatic heating controls and efficient lighting systems.”
It all sounds very lofty and ideal, but the reality is that, as a landlord with many tenanted properties large and small, the National Trust is being forced, usually by local government Environmental Health Officers whose understanding of esoteric issues such as breathability and traditional construction is minimal at best, to comply with a variety of “decent homes” standards which many private owners of historic buildings would find unacceptably harmful to the qualities that led them to buy in the first place.
The standards themselves are broad, and set out with the best of intentions, but achieving those standards is being left in the hands of people who simply do not understand the fundamental difference between what can be achieved in a modern, air-tight rabbit hutch by a volume housebuilder, and what can realistically be achieved without long-term damage in almost any property built before about 1920.
The first I knew of all this was when the NT's property manager phoned me querying the very specific nature of the remedial works being required by Environmental Health, to an unlisted 17th century cottage on one of their local estates. The property does indded have very serious damp problems, most of which are condensation-related as the bathroom and kitchen are internal and poorly ventilated, and the last tenant never opened the windows. Some choice extracts from the notice are reproduced below:
HOUSING ACT 2004
Sections 11 and 12
The Authority … serve this Improvement Notice under Section 11 and require you to take the remedial action specified. Details of the Category 1 hazards together with the remedial action required are contained in the Schedule attached.
A person, on whom an improvement notice is served, commits an offence if s/he fails to comply with it and is liable on summary conviction to a fine not exceeding level 5 on the standard scale.
Nature of the hazard :- Excess Cold; Damp and Mould Growth; Falling on Stairs; etc (yes, they really did add “etc” as a hazard! Bit of a catch-all, that one)
The deficiency giving rise to the hazards:-
Absence of heating system; Defective windows; Rising damp to walls; Rising damp to floors; Insufficient insulation to walls and ceilings; Inadequate surface water drainage; Defective brickwork; Defective roof; Steep stairwell without banister; Absence of mechanical extraction to Kitchen
Nature of remedial action required to be taken:-
Insulate Loft Space
Increase insulation of loft space to 270mm using quilted insulation or apply equivalent to 1st floor ceiling to provide a 'U' value of not more than 0.16 and to comply with current Building Regulations.
Damp Proof/Insulate Walls
Treat all walls to the ground floor to prevent rising damp
Carefully remove for re-use, existing skirtings (where present), and door linings. Hack off all damp and defective plaster to a minimum of 1m above the proposed damp proof course, or 150mm above the level of the damp which ever is greater.
Key brickwork ready to receive new rendering. Inject a chemical horizontal/vertical damp proof course guaranteed by an insurance bond for a minimum 20 year period. This work must be carried out by a specialist contractor.
For internal walls:-
render exposed areas using a suitable sharp sand and cement mix, incorporating a waterproofing additive and salt inhibitor as instructed by the specialist contractor.
For external walls:- (Dry Line)
Hack off any loose, sodden or perished plaster to all the ground and 1st floor external walls. Provide tanalised softwood battens and fix vertically to full height using plastic wallplugs and brass screws. Battens to be suitably sized and spaced to allow for insulation slabs to be fitted to bring "U" value of walls up to current Building Regulations standard. Cover battens and insulation slabs with 9.5mm thick foil backed plasterboard, fixed with galvanised clout nails or corrosion resistant screws.
Scrim joints to plaster board and finish walls with a 3mm plaster setting coat, flush with existing plaster where applicable.
Lay New Damp Proof Floor
Remedy the ground floor dampness and for that purpose take up the existing surfaces of the rooms to the ground floor excavate to a sufficient depth and construct a new floor incorporating an efficient horizontal damp-proof membrane; the damp-proof membrane to be carried without a break vertically up the walls to a sufficient height above the DPC membrane, upon completion the interior surfaces of the walls to be re-plastered.
Repair Chimney Stack
Renew and re-point new brickwork to chimney in suitable cement.
Cut out defective brickwork from the chimney stack replace with new or sound second-hand bricks set in cement mortar, renew defective pointing, defective soakers, flashings, and fillets (soakers and flashings to be in code 5 lead, and fillets to be in suitable mortar mix incorporating a waterproofing additive.) Seal or cowl pot/s, leave roof sound and watertight on completion.
Rake out all loose and perished brickwork pointing to all facades of the property, specifically to the right façade of the property as you look on from the adjacent road, to a depth of 20mm. Brush out debris, wet and re-point in suitable mortar, with the joints finished to match existing in all respects.
Fascinating, isn’t it?
What really concerns me is how many people (who don't have the NT's experience) would meekly comply and therefore do more harm than good to their properties? Not long after this notice was served, I chanced across another notice from Env Health requiring PVCu windows to be installed in a listed building, with cement repointing and plastic gutters being specified too. The bullying manner and prescriptive “tick box” way in which some EHOs are approaching the task is bad enough when pushed at the NT, but where private landlords are concerned, threats of legal action if specific treatments – often injected damp proof courses, double glazing and dry-lining – are not carried out, lead to all manner of terribly damaging works being done, “on council orders” and therefore often without the necessary consents.
5 months ago