Low Carbon Buildings -Retrofit House
1. Introduction
房屋现在的状况，英国威尔士房屋改造的目标，本文将通过什么来实现目标
我们的目标不仅仅是要让 carbon reduction over baseline 95%，也要让这栋老房子变成一个
全年都很舒适的地方，它消耗的热量更少，对子孙后代的环境影响更小，并且也要考虑修
建的费用问题。我们都想要一个温暖健康的家。一个全年都很舒适的地方，它消耗的热量
更少，对子孙后代的环境影响也更小。
在老房子里实现这一点比在新房子里要复杂得多，因为标准的阁楼和空腔墙隔热等措施可
能是不可能的。为了让你的家做出最好的选择，让你的钱得到更好的结果，在你开始做决
定之前，先了解你的家是很重要的
2. Domestic retrofit operational carbon
2.1
Analyze the current condition of the house
This is a typical terrace house in wales in the early 20th century. The following is
the analysis of this house. Through the table, we can better carry out the next
step -- specific transformation with SAP software. We need to find out what's
wrong with the house before we can make a full conversion. The link to the SAP
Sensitivity Tool for this house is：http://bit.ly/3796TFG
Location
South wales
Housing type
Pre 1919 mid of terrace house, typical
welsh house with two floors
floor area
80 m²
South facing roof area
20 m²
Wall area
2.5×40=100 m²
Fabric
Ventilation
• 300mm external solid stone wall, plastered,
no insulation
• no insulation floor
• The roof is clay tiles with 50mm insulation
between the rafters
• Double Glazed windows, with a 6mm air gap,
PVC frames U value = 3.0 W/m²·K
• The doors are PVC frame U value = 3.0
W/m²·K
Natural ventilation
Heating system
new mains gas combi boiler
Renewable system
none
We reformed from four aspects: fabric, ventilation, heating system and
renewable systems. We can see that the old house has no insulation for walls
and floors. In order to reduce heat loss, insulation is very important, so in the new
plan, advanced technology and different materials will be used to change the uvalue of walls, floors and Windows. Existing heating systems will also be
changed, and more solar power will be used.
2.2 Changes
This is the new plan link to the SAP Sensitivity Tool for this house: https://bit.ly/3bmeB1F
从原来的 carbon reduction over baseline 56%变成 95% ，一共有 7 个项目被改变了。计算部
分新的 U-value 时可以用老师给的网站（https://www.uvalue-calculator.co.uk/）进行计算，
也可以参考供应商提供的产品细节。
下面是具体的操作过程：
 Changed fabric material U-values (wall, roof and window)
Existing wall
changed wall
Material
solid stone
no insulation
solid stone and
Kooltherm K118 Insulated
Plasterboard
Thickness
300mm
300mm+52.5mm
U-value
2.10W/m²·K
0.34W/m²·K *
Build-up
Existing roof
changed roof
Material
clay tiles with insulation
between the rafters
Thickness
50mm insulation
clay tiles with Kingspan
Kooltherm K7 Pitched Roof
Board insulation
100mm insulation
U-value
0.6W/m²·K
0.2W/m²·K *
Existing window
changed window
Material
Double Glazed windows, with
a 6mm air gap, PVC frames
Crystal Clear Double-glazed
windows, with a 10mm air
gap, White uPVC frames
Thickness
-
70mm
U-value
4.8W/m²·K
1.4W/m²·K *
Build-up
Build-up

Thermal bridge

infiltration rate

solar PV panels
Solar PV panels
Material
Crystal Clear Double-glazed windows, with
a 10mm air gap, White uPVC frames
Thickness
70mm
U-value
1.4W/m²·K *
Build-up

cost implications
面积
单价
安装费
总价
Wall
roof
window
Pv panels
3000
Total cost

*cost=area ×Price per square meter

大概做一个费用分析的表格

alternation installation plan
写一个安装计划，哪个先改装，哪个后改装
20 世纪以前建造的房屋外墙一般都是这种坚固的石头或者砖，这种墙没有 cavity wall
insulation（找一个石头墙的图） 想要加强墙面的保温效果，只能选择外墙隔热和内墙
隔热，相比外墙隔热，内墙隔热安全性高，保温材料和施工成本低，且使用寿命长，
易于安装。所以内墙隔热会被用来增加墙的保温效果。根据威尔士地区对翻新
domestic existing buildings 的要求，the U-value for internal or external wall insulation
should be around 0.30 W/m²·K.下面的表格是 the details of the wall.
*然而通过对 SAP 工具的操作，墙的 U-value 在 0.30-0.35 W/m²·K 之间时 the value of
carbon reduction 相同
Part 2 - Carbon footprint of a building element

the carbon footprint of an “element” as described above.
carbo
Part 3 – Operational vs Embodied Carbon

Compare the Operational Carbon (Part 1) over the lifetime of the measure
chosen (e.g. a boiler will last 15 years) against the saving in Embodied Carbon
(Part 2).
Part 1 Domestic retrofit operational carbon
http://bit.ly/2wRyXRC
http://bit.ly/2TPvBHT
http://bit.ly/2IGkpqN
Part 2 Carbon footprint of a building element
Part 3 Operational vs Embodied Carbon
Conclusion
Reference