Presentation by Doug Johnson from Mesh Energy from RIBA 2030 Climate Challenge Rising to the performance challenge: What it means for Architects webinar on 24th March.

1. www.mesh-energy.com
IES VE Case Study:
RIBA 2030

2. www.mesh-energy.com
Who are Mesh Energy?
We are independent energy consultants
Purpose
“To inspire and forge a sustainable legacy”
Mission
“To instil confidence and pride in low energy
projects through intelligent design”
How can we help you?
— Holistic and independent
— Deliver intelligent design and feedback
— Your partner in ‘simplifying the
sustainable energy landscape’
— Support at every project stage

3. www.mesh-energy.com
© Snug Architects
Low Carbon Housing Development – Case Study

4. www.mesh-energy.com
Low Carbon Housing Development – Introduction
Location: Home Counties
Stakeholders:
Client: Private Developer
Architect: DB Architects
Scope: Development of 9 No. 3, 4 & 5 bed homes
Site challenge: ‘Sensitive’ building site
Design challenge: How did Passivhaus design
compare to new 2022 Building Regs, RIBA 2030
and Net Zero Carbon?

5. www.mesh-energy.com
Low Carbon Housing Development – Software Setup
Proprietary Software & Calculators
Part G Water Calculator
Feasibility -Tech Strategy/£/RHI
Operational
Energy
Embodied
Carbon (& Cost)
Health and
Wellbeing
Potable
Water
CIBSE TM54
RICS Pricing Database
CIBSE TM59 (Thermal comfort)
CO2 & Daylight
Building Regs
Verified EPDs

6. www.mesh-energy.com
Low Carbon Housing Development – Operational Energy
Operational Energy reduced by 86% against Ofgem
benchmark
Building fabric & airtightness:
- Roof: Clay tile, insulated between and over floor
joists
- Brick and Timber clad SIPS
- Insulated beam and block with screed finish
- Triple glazed windows
- Airtightness 0.6m3/m2h
Renewable Technology
- Air source heat pumps (heating and hot water)
- MVHR
- Centralised site solar PV
Current RIBA 2025 RIBA 2030 House Type 1 House Type 2 House Type 3 House Type 4
Operational Energy Embodied carbon Potable water usage

7. www.mesh-energy.com
Low Carbon Housing Development – Operational Energy
Element Part L RIBA 2025 target RIBA 2030 target Proposed design
External walls
0.18 0.12 <0.1 0.10
Cold roof
0.13 0.11 <0.1 0.10
Ground Floor
0.13 0.11 <0.1 0.10
Windows/doors
1.4 1.0 <0.8 0.80
Air tightness,
m3/hr.m2@50Pa 5 1.5 <0.6 0.6

8. www.mesh-energy.com
Low Carbon Housing Development – Embodied Carbon
Embodied Carbon reduced by 73% against RICS
Whole Life Carbon method
Current target: 1200kgCO2e/m2
2030: <625kgCO2e/m2
Our design: 329kgCO2e/m2

9. www.mesh-energy.com
Low Carbon Housing Development – Overheating & Ventilation
Design met all overheating and
ventilation health design criteria for RIBA
2030
- Hybrid brick and SIPS added thermal
mass
- Overheating of design stress tested
out to 2070
- Hit and miss solar shading integrated
to reduce daytime overheating

10. www.mesh-energy.com
Potable water: Step-change to efficient
fixtures and fittings
Main adaptation: Transition away from
baths
Main adaptation: Inclusion of rainwater
harvesting
Low Carbon Housing Development – Water Efficiency
Water use Type 1 Type 2 Type 3 Type4
Number of occupants 4 4 5 6
Kitchen sink taps (litres/min) 8
Dishwasher (litres/place setting) 1.25
Washing machine (litres/kg dry load) 8.17
Waste disposal (litres/use) 1
Bathroom sink (litres/min) 6
Shower (litres/min) 12
Bathroom dual flush WC (4/2.6 litres) 3.062 (effective)
Rainwater* harvesting contribution
(litres/person/day) 20.8 20.8 25.6 28.1
Water consumption (litres/person/day) 72 72 67.7 65.3
Water usage reduced by 45% against current
standards

11. www.mesh-energy.com
Low Carbon Housing Development – RIBA 2030 Summary
86% 73%
45% 2070+