Retrofit Designer qualifications
David Manns will be the Retrofit Designer for this project and is qualified as a Retrofit Coordinator (Level 5 Retrofit Coordination and Risk Management - June 2020)
Review Guidance
This retrofit design has considered the guidance in Sections 4 & 5 of PAS2035 and will provide a 'Heating System' approach to retrofit.
Review assessment information
The information that has been captured by the PAS assessments and the technical assessments is sufficient to prepare the design
Retrofit Coordinator activities
The Improvement Option Evaluation for this project will be provided by the Retrofit Coordinator.
Scope of the design
The scope of the design has been agreed with the Retrofit Coordinator. The intended outcomes are in line with the Energy Company Obligation (ECO) requirements and are intended to assist in reducing carbon emissions, maintaining security of energy supply and reducing fuel poverty.
PAS2035 compliant design (EWI)
The install must be completed in line with EPS EWI Install Guide, EPC Basecoat (EWI-220), SiliconeRender (EWI-075) and BBA Agrement Certificate.
Ventilation assessment (insulation measures)
The ventilation assessment has identified that the existing ventilation system does not meet the requirements of PAS2035 - Upgrades required are listed in the Condition of the existing building
A condition survey has been completed and this suggests that the property is in a good state of repair and that no remedial work is required prior to the installation. The co-ordinator has visited the property and finds it in excellent condition
Planning conditions
No planning conditions imposed by the local authority
Products & material specification
Full details of the products specified are listed below
EWI
This install must be completed in line with EWIpro, EPS, Grey and as per PAS requirements needed under PAS2035 requirements . We have also added the manufacturers specifications below with all the details. The roof line at the rear of the property will need to be extended in line with the thermal bridging drawing from EWI-Pro - use XPS insulation at the roof line. At the DPC remove render before insulating with XPS, include under the door frame. All pipes and lights must be extended to make room for 90mm insulation. Insulate the utility cupboard with XPS. The boiler flue will need to be extended by a qualified gas engineer. As per the EWI-design the insulation will terminate at the bay windows. The extension of the property is not included in quotation under the Green Homes Grant scheme. The installations will be carried out using the amber details from the NIA/Inca/Swiga guide increasing the inherent technical risk by 1. This has been allowed for in the risk assessment.
Ventilation assessment (insulation measures)
We are installing External Wall Insulation, EWI Pro, EPS Grey. The assessor has noted the following in the ventilation assessment during his Retrofit Assessment: It has been identified that the existing ventilation system does not meet the requirement for PAS 2035. Internal doors for bedroom 2, bedroom 4, kitchen/diner, W/C and the bathroom shall be undercut prior to installation. Trickle vents are required in all habitable rooms, i.e. the living room and bedrooms 1 to 4. The kitchen currently has standard trickle vents fitted. We will not be installing new trickle vents, the windows have aluminium frames which will not support trickle vents. The customer is however, installing new double glazing windows with trickle vents in January 2022
Moisture Management
The property is occupied by 4 people, there are no signs of damp, mould or condensation at the property. Extract ventilation is installed in all wet rooms. i.e. the kitchen, WC and bathroom room 1, all extract fans are in working order. However new dMEV fans will be installed in the kitchen and Bathroom 1 only. An air flow test will be required for the extract fan in the WC. Purge ventilation is available in all habitable rooms. Trickle vents are required in all habitable rooms, i.e. the living room and bedrooms 1 to 4. A standard model of trickle vents will be installed prior to install. The kitchen currently has standard trickle vents fitted.
Physical interactions between measures
Design details for measures that physically interact are shown in the design details document and must be followed to minimise thermal bridging and maintain airtightness. The measures interaction matrix for EWI and the loft insulation already present is yellow which suggests measures interact or may connect and require construction details.
Resilience to rainwater ingress or flood
The property is in a good state of repair, is in a moderate exposure area and has a very low flood risk
Maintenance requirements
Handover (Ventilation)
Information to be provided regarding the cleaning and replacement of air filters in mechanical
ventilation systems and the consequences of disabling any ventilation systems, for example
blocking off air vents. The householder will be provided with the manufacturers operation
instructions.
Assessment and handover documents
The retrofit installer will be provided with a copy of the retrofit assessment and the retrofit design.