Proposed works

External works, ground levels, surface drainage

✓

Moisture-related maintenance work

✓

Re-pointing of mortar joints

Re-rendering or plastering of walls

Internal wall insulation

External wall insulation

✓

✓

Cavity wall insulation

Fit flue damper or flue balloon

Block flues

Window maintenance

✓

✓

Secondary glazing

Retrofit double glazing into existing window frames

Windows & external door replacement

Draughtproofing

High level of airtightness

Internal redecoration

Insulation of suspended timber ground floor

Replacement insulated solid concrete floor

Maintenance work to roof and drainage

Roof insulation on flat ceiling

✓

✓

Roof insulation on pitched ceiling

Re-plumbing

New room heaters

Heating system replacement

✓

✓

Heating controls upgrade

✓

✓

Domestic hot water storage upgrade

Solar hot water

Re-wiring

Change to 100% low energy lighting

✓

✓

Standalone extract ventilation

Whole house demand control mechanical extract ventilation

✓

✓

Mechanical ventilation with heat recovery

Moisture management

There is a significant rising damp problem to front (extending to bottom of central wall of house separating Kitchen and Livingroom. Until this is resolved to bring moisture levels permanently down to an acceptable level, no wall insulation should be considered.

Impacts of intervention to be assessed

External walls

No insulation to front wall: see above.

Positive

Ensuring front wall dries out will add to longevity of the house and survival of built heritage

Windows

No change to rear windows, which are of a good modern specification. Move these windows forward during external wall insulation works to re-instate the traditional external jamb depth of ~110-140mm. This creates a low thermal bridging condition and facilitates the installation of airtightness tapes at reveal-window junction (before completion of internal plastering of reveals).

Low

Alteration of contemporary windows to the rear does not affect internal features.

Front door

Insert insulation in recessed panes of front door. (U-value improves from 2.59 to 1.23 ).

Medium

This measure is additive and reversible (but will visually detract from the door)

Floors

No work to suspended timber floor until moisture issues solved

None

Attic insulation

300mm sprayed cellulose in the attic (U = 0.13 W/m2K).

None

No impact on original fabric

Tank insulation & attic pipes

Insulate water tank and pipe insulation.

None

No impact on original fabric

Heating system replacement

Install new condensing combi-boiler (90.1% efficient in lieu of 68% efficient) for space heating and hot water. Install solid fuel stove (in lieu of 30% efficient open fire). Remove cylinder.

None

No impact on original fabric

Heating controls upgrade

Time and temperature zone control and boiler interlock - two room stats, one on each floor, each with independent time control (level 3)

Low

A wireless control system can be considered if routing of cabling is proving problematic

Ventilation

Complete installation of ventilation system by fitting extract unit to kitchen ceiling connected to attic fan by ducts running through prefabricated housing fitted to kitchen ceiling, external wall insulation and cores in concrete eaves

Moderate

Housing from vent to core through outside wall in ceiling will be pre-finished and discrete.

Using the correct equipment there should be no risk of damage to eaves due to drilling.

If a vent if proposed to the front façade, the cover detail should be considered carefully to minimise impact on the façade

Low energy lighting

Fit 100% low energy light bulbs.

None

Moisture management

In the maximum upgrade project, it is assumed that the moisture issues have been dealt with and the wall dried out sufficiently. Measures suggested are the insertion of a physical damp proof course at ground level and again at internal floor level, the stripping of both plaster and render, and application of new conservation plasters that are salt blocking but highly vapour permeable.

High

The removal of internal plasters may have a significant impact on the house.

External walls

Rear wall externally insulated

Front wall to be internally insulated with 100mm cast Tradical hemp-lime roof mix (U-value 0.44). This type of insulation has special characteristics that help pull moisture out of a wall should some level of moisture accrual still occur. 

Moderate

The application of an internal insulation layer will have a visual impact on existing cornices and window reveal depths. The board will either have to be tapered up to the existing cornice or the cornice removed and reproduced

Underfloor insulating of front floor

Lift floorboards, lay mineral wool quilt or cellulose insulation tightly slung between joists, install tapes, air and vapour control layer and re-install floorboards.

Low

If floorboards can be removed without damage, the works should have no impact on the existing fabric

Windows

Treat rear windows as set out in minimum project above.

Install secondary glazing behind traditional sliding sash window of Livingroom.

Low

No impact on original fabric or windows. Will ensure future retention of original timber sash window

Roof

Upgrade to rear roof, pitched ceilings U=0.49 W/m2K and flat ceilings (0.13 W/m2K)