REMI - Outline performance and technical specifications

Transcription

1 REfurbishment as Manufacturing Industry REMI Prject 24 May 2016 REMI - Outline perfrmance and technical specificatins WP2.2 - WP3.1 Deliverable Intrductin The cncept f deep retrfit is nt new. The main cnsideratins are arund specificatins, cst, time and incnvenience t the ccupant. Hwever, when cnsidering the advantages f pre manufactured elemental cmpnents and the enhanced quality this wuld bring, as well as the ability t reduce time and cst n site and ultimately reduce incnvenience t the ccupants, a much imprved experience and higher quality utcmes can be predicted. An utcme-based perfrmance specificatin takes n a new apprach based nt arund the chice f materials r prducts that can enhance r imprve the existing structure r fabric, but ne based n building perfrmance standards (e.g. guaranteed energy and indr air quality perfrmance) cmbined with a whle-huse refurbishment apprach. This allws fr a lng term prduct warranty and is likely t result in an ver-cladding f the existing structure - in essence, building a new huse ver the existing ne. The existing fabric can therefre be discunted when designing and predicting the thermal perfrmance f the refurbishment, with any insulatin cntributin prvided by the existing fabric nly imprving the utcme f the finished retrfit wrap. But it s the baseline wrap specificatin that is critical. Frm a slutin prvider perspective the apprach we wuld take wuld be t base the wrap design and technical specificatins n an equivalent new build: The fabric perfrmance / U-values ptentially fr all elements, thus reducing heating demand and cnsequently gas cnsumptin; PV t generate electricity; Energy planning. Cnsidering hw these culd be delivered in a refurbishment slutin. Using the Fabric First apprach, the envelpe must be designed using detailed energy perfrmance assessment sftware (i.e. dynamic energy mdelling, IES, SAP2012, etc.) t predict regulated annual energy cnsumptin figures fr the fllwing: Heating; Dmestic ht water; Lighting;

2 Ventilatin. We als need t estimate energy requirements fr cking and appliances. Varius benchmarks are available including figures used by BRE, Passivhaus and prpsed fr use by the Innvate UK Building Perfrmance Evaluatin prgramme and f curse the figures used in the Dutch Energiesprng mdel. In additin t the annual cnsumptin figures, calculate the peak heating lad requirement. Once peak lad and annual cnsumptin figures have been determined, we have t cnsider ways f meeting these demands and pssibly cnsider alternative fuel surces and technlgies. Heating Cnsider the existing specificatin and ways this can be imprved within the cnstraints f the current design t lwer annual and peak lad cnsumptin. Increasing regulatry requirements t have gas safe apprved staff t discnnect and recnnect appliances. Dmestic ht water Cnsider practical ways in which dmestic ht water cnsumptin culd be lwered. In UK culture baths need t be retained pst refurbishment. Hwever shwers ver baths will be prvided. Cnsider electric heated shwers. Lighting Calculate the energy cnsumptin based n LED lighting and crss reference t the SAP lighting assumptins. Ventilatin Lk at all frms f ventilatin and calculate bth the peak lad and annual cnsumptin figures t achieve the desired perfrmance related t air quality (CO 2, humidity). Appliances / Cking. This research can be split int three main bjectives as fllws. Perfrmance Specificatin (Custmer s perspective) Befre a technical specificatin is created, a baseline perfrmance specificatin is needed. Frm the custmer s perspective this cvers aspects f cst, cmfrt, cnvenience etc. Hwever, in rder t establish what an achievable perfrmance specificatin wuld be, it is helpful, t lk at a design energy cnsumptin limit per square metre f flr area f an equivalent rbust new-build dwelling. This will give flexibility in huse designs/sizes f accmmdatin. Typical figures fr a 5 persn dwelling are reprted belw. This shuld cver a number f elements: Cst Maximum target annual dwelling running cst f N additinal maintenance cst t prperty wner fr elements included in the slutin, the duratin f the energy plan. Cmfrt (wellbeing) Internal temperature fr heating - guaranteed 21 C fr living areas (i.e. kitchen, living rm); 18 C fr bedrms;

3 Summer verheating criterin n mre than 1% f annual ccupied hurs ver a cmfrt temperature f 28 C (living areas) and 26 C (bedrms) (NHBC Fundatin, NF 46, Overheating in new hmes, 2012) ; Indr Air Quality - CO 2 levels between 800 t 1000ppm (CISBE Guide B, 2005) used an indicatr f adequate IAQ; Humidity between 40 and 60% fr gd IAQ; Nise Levels - Minimum 43db (Airbrne sund insulatin) fr separating walls; Maximum vlume f dmestic ht water apprx. 30 litres per day per persn delivered by ht water strage and/r electric shwer at 55 C r apprx. 40 litres at 40 C (crrespnding t 1800kWh/yr, ttal energy cnsumptin); Daylighting Daylight factr between 2 and 5 (CIBSE Lighting Guide 10); Secured by design principles t PAS24 Standard. Aesthetics Planning/kerb appeal and lcal integratin int the vernacular; External appearance t be maintained fr 30 years; Engagement f the custmer in the prject design and chices; Tlerant t the effects f climate change. Time n site Delivery f the wrk within 10 wrking days; Tenant in situ. Tenant supprt Engagement in the prcess (familiarisatin with the cncept); Pst ccupancy supprt; Prtectin f persnal/peratinal data. Scial Value Crprate and scial respnsibly. Scial ecnmic return n investment, i.e. regeneratin f the area. Technical Specificatin (Slutin prvider respnse t perfrmance specificatin) The prvider f the refurbishment slutin will then need t cnsider the technical specificatin that will deliver the perfrmance slutin set by the custmer. There will nt be a single technical specificatin that will achieve this and different slutin prviders may chse t fulfil the perfrmance specificatin thrugh different appraches. This sectin therefre describes ne way in which this culd be achieved. T this regard, first sme general cncepts fr a better understanding f a huse energy perfrmance are reprted. The energy perfrmance f a huse cnsists f three parts as fllws: Building-bund use. This is the energy needed fr space heating and cling, water heating, ventilatin and auxiliary energy (the energy required t perate building-bund energy installatins) f the huse in the UK this is synnymus with the regulated energy (excluding lighting). At a living rm temperature f an average C and a healthy indr envirnment (including ventilatin), the regulated energy requirements depend largely n the perfrmance f the prperty and the external cnditins. A typical maximum building-bund use is between 3,000 and 4,000 kwh per huse per year. User-bund use. This is the energy cnsumed by the user fr lighting the huse, cking and husehld electrical appliances unregulated energy. A standard family has a user-related energy cnsumptin f between 2,500 and 4,000 kwh.

4 Generatin. Fr net zer peratin, the lcal generatin f energy, fr example by means f PV panels, shuld be sufficient t cver the maximum building and user-bund energy cnsumptin. Experience tells us that in rder t achieve these set parameters, the main building fabric shuld be designed t an elemental U-value f apprx. 0.18W/m 2 K. Under building regulatins in the UK there are specific perfrmance requirements fr refurbished elements, hwever we are hping t push the perfrmance up t a new build level based n the technical specificatin reprted belw. They can be used as key perfrmance indicatrs t manage the expectatins f the prject and prvide mre certainty and cnfidence in the mdel. In view f the perfrmance guarantee, designing the slutin, the slutin prvider may cnsider trade-ff between mre expensive lnger lasting ptins. Perfrmance Assurance Energy perfrmance t be guaranteed fr 30 years after refurbishment this culd be achieved by a cmbinatin f lng lasting cmpnents and systems cupled with lwer maintenance and replacement interventin r by lwer capital cst cmpnents and systems that need t be replaced mre frequently. Quality f envirnment - indr climate standards, as based n the perfrmance specificatins, guaranteed fr a perid f 30 years. The supplier guarantees the cmplete perfrmance specificatin with relevant elements guaranteed fr a standard fr a perid f 30 years. Fabric perfrmance Flr 0.18 W/m 2 K (where cnstructinal upgrades allw); Rfs 0.11 W/m 2 K; Windws 1.5 W/m 2 K; Drs 1.4 W/m 2 K; Air tightness less than 5 m 3 /hr/m 2 at 50 Pa (minimum allwable standard is 10 m 3 /hr/m 2 at 50 Pa). Energy perfrmance requirements Maximum design annual space heating demand f 30 kwh/m 2 ; Maximum design annual DHW demand f 25 kwh/m 2 ; Maximum design annual appliances/lighting/cking demand f 45 kwh/ m 2. Onging mnitring t verify actual building perfrmance and identify disagreements with the expected perfrmance. Mnitring devices t be installed and maintained at the supplier cst. Systems in place t highlight ptential issues and implement rectificatin/repair r alert if due t ccupant behaviur. Time n site Slutin prvider t cmplete the refurbishment within 10 wrking days n site. Tenant supprt thrughut the prcess and in their refurbished dwelling especially w.r.t. peratin f new systems, impact f behaviur n energy use. Must be dne sensitively nt big brther. Design Quality

5 Tenant satisfactin als critical t achieve prduct buy-in (e.g. quality, kerb appeal, design uplift); Optimise building quality design t meet custmers satisfactin (e.g. aesthetic); Gd quality design as key aspect f sustainable develpment. Scial Value Crprate and scial respnsibly; Sci-ecnmic return n investment. Added value Engage with a prperty MOT, reduce reactive maintenance csts at surce; Custmer Service prcess. Summary This is nt just abut refurbishment; this is abut an engineered prduct slutin based upn the capabilities f the manufacturing industry that delivers a mre predictable slutin. This is as much abut guaranteed perfrmance thrugh design as it is abut imprvement f existing stck. The utcmes f this methd are as imprtant as the technical apprach and s it is abut a fully integrated apprach and nt just ne f specificatin and site delivery. This is a hlistic, lng term, assured delivery methd ffering predictability t wner, user and investr.