Project Overview:
Background:
This scheme was commissioned by North East Derbyshire District Council and managed by Rykneld Homes, a social housing specialist that is responsible for the management, maintenance and improvement of around 7,600 properties. The work entailed installing PermaRock external wall insulation (EWI) systems to 640 homes and a variety of archetypes, including Reema Hollow Panel (285), Airey (38), Wates (156), Unity Type II (62), Wimpey No-Fines (96) and BISF Type A1 (3).
The Brief:
A key requirement was that the chosen system must improve the thermal performance of the homes. As an average, the targeted energy reductions were 6,994 kWh/year per property, together with annual carbon savings of 1,511 kg per property. Total savings for all 640 homes would therefore equate to 4,475,883 kWh/year (energy) and 966,790 kg/year (CO2). Total space-heating savings would be around 51,006 kWh/m2/year.
Design & Specification:
The system chosen for the scheme was PermaRock’s 90 mm EPS Premium External Wall Insulation System, together with PermaRock Dry Dash Finish, in a bespoke ‘Rykneld Spar Blend’ colour.
The PermaRock EPS Premium is a lightweight external wall insulation system based on expanded polystyrene (EPS) and microscopic particles of graphite for enhanced thermal performance. It can be installed in thicknesses up to 300 mm and it can assist in achieving Code for Sustainable Homes Levels 4 - 6 and Passivhaus Standards. It also enables the creation of extremely airtight façades.
PermaRock Dry Dash comprises a self-coloured, polymer-enriched, mineral-cement dashing mortar, into which a choice of coloured dashing aggregates may be applied. The aggregates are pre-washed and screened to ensure a consistent size, and different colours may be blended together to produce a range of finishes.
The standard range includes 6 colours of Dashing Mortar and 32 blends of Dashing Stones. However, special colours may be produced subject to minimum order quantities. In this case, in order to preserve the character of the properties, the client requested its own bespoke colour blend using aggregates from a nearby Derbyshire quarry.
The resulting finish is attractive and affords lasting protection against the weather. It presents an effective barrier to air permeability, it is durable and low-maintenance, and it will resist discoloration.
In addition, PermaRock Brick Slips were used as subtle design features - in this case, soldier courses beneath the windows. They afforded an effective but inexpensive way of adding character and visual interest to the otherwise homogenous Dry Dash finish.
Result:
Work is progressing well, according to schedule. The accompanying photographs show the improved appearance of the properties, thanks to the use of the new Dry Dash finishes and Brick Slips.
Resident feedback has been extremely positive. One tenant said: “The homes are warmer and in winter it’s going to be great. It should save us a lot on electricity because we’re not going to have to have the heating on so much.”
Another commented: “It’s going to cut back on bills, which is what everybody’s wanting, and it’ll be a lot more comfortable. Even the general outlook and the feel of the place is better.”