Buildings 2011, 1, 4-15; doi:10.3390/buildings1010004
buildings
ISSN 2075-5309
www.mdpi.com/jou nal/buildings/
A icle
Re o i ing o Ene gy Habi abili y in Social Housing: A Case
S udy in a Medi e anean Clima e
Ra ael Suá ez * and Jessica Fe nández-Agüe a
Uni e si y Ins i u e o A chi ec u e and Building Science, Highe Technical School o A chi ec u e,
A . Reina Me cedes, 2, 41012 Se ille, Spain; E-Mail: j e nandezague [email protected]
* Au ho o whom co espondence should be add essed; E-Mail: sua [email protected];
Tel.: +34 954 551 630; Fax: +34 954 557 024.
Recei ed: 29 No embe 2011; in e ised o m: 17 Decembe 2011 / Accep ed: 21 Decembe 2011 /
Published: 27 Decembe 2011
Abs ac : Much o he esiden ial sec o in Spain is obsole e, wi h inadequa e condi ions o
com o and high ene gy consump ion. Fo his eason mos o he po en ial o imp o ing
ene gy e iciency lies in he exis ing esiden ial sec o , which equi es upg ading o mee
he quan i a i e and quali a i e changes equi ed a p esen . This s udy o speci ic cases
aimed a es ablishing gene al c i e ia o ac ion has been p omp ed by he di icul y in
p oposing gene al in e en ion s a egies. This pape p esen s a case s udy o he ene gy
e o i o 68 social housing uni s in Co doba (Spain) e alua ing hei ene gy consump ion,
wi h a iew o imp o ing he building’s ene gy balance and indoo he mal com o , on
which use com o depends.
Keywo ds: ene gy e iciency; e o i ing o social housing; he mal com o ;
imp o emen o habi abili y
1
1.
.
In oduc ion and objec i es
The eno a ion o esiden ial buildings p o ides an excellen oppo uni y o he imp o emen o
ene gy consump ion and indoo clima e. Upg ading he he mal en elope insula ion and he use o
passi e measu es such as he use o sola con ol in he summe ime lead o ene gy sa ings and an
imp o emen in indoo and use com o .
OPEN ACCESS
Buildings 2011, 1
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The s udies ca ied ou by Ramesh e al. [1], Sa o i and Hes nes [2] and He nández and Kenny [3]
show ha when analyzing he li ecycle o esiden ial buildings he use phase accoun s o be ween
80–90% o he o al ene gy consump ion. The e o e, he educ ion o ene gy demand du ing he use
phase, pa icula ly making use o passi e sola design s a egies, is he mos impo an ac o o
conside when designing he building.
The la es Ene gy Pe o mance o Buildings Di ec i e, EPBD [4] es ablished clea ins uc ions o
la ge e u bishmen s, aimed a inc easing insula ion equi emen s o make he mos o he g ea
po en ial o ene gy sa ing in buildings.
The e a e a signi ican numbe o ene gy e o i ac i i ies in No he n and Cen al Eu ope,
cha ac e ized mainly by a high le el o he mal insula ion. Howe e , in egions wi h a Medi e anean
clima e ewe in e en ions a e ca ied ou , and hese a e usually linked o In e na ional [5-8] o
Na ional P ojec s [9-12] including bes p ac ice case s udies in Spain, Po ugal, I aly, and G eece.
The mal insula ion le els in Medi e anean clima es do no need o be as high as in o he pa s o
Eu ope. Howe e , gi en he g ea e deg ee o sola adia ion his s a egy should be combined wi h
o he measu es such as he mal ine ia, sola con ol, nigh en ila ion, o educed in e nal gains. Mos
case s udies ha e e alua ed ene gy consump ion and sa ings, bu ew examples o e o i ac ions
execu ed ha e been assessed in e ms o indoo he mal com o condi ions [7,13] In hese
Medi e anean case s udies, he alues o indoo empe a u e in summe o en exceed he indoo
com o band as a esul o sola adia ion.
The unique na u e o each e o i p ojec and a wide ange o clima e zones make i di icul o
es ablish guidelines o ac ion. The e is he e o e a need o de ine he mos e icien cos and
pe o mance solu ion o each case. This has p omp ed he p oposal o speci ic case s udies o
es ablish gene al c i e ia o ac ion.
The building unde s udy consis s o 68 social housing uni s o en , wi h comme cial p emises and
a ga age, buil in 1994 by he municipal cons uc ion company Vi iendas Municipales de Có doba
(Vimco sa) and inanced by he S a e Fund o Employmen and Local Sus ainabili y [14].
Cons uc ion wo k was ecen ly comple ed on he e o i p ojec ini ia ed in ea ly 2010 by he
a chi ec Ra ael Suá ez.
Gene ally, p oposals o ene gy ehabili a ion a e based on he p omo ion o ene gy sa ing and
e iciency, concen a ing on he educ ion o CO2 emissions and use s’ ene gy consump ion. The main
aim o his s udy is o inco po a e imp o ed he mal habi abili y condi ions in he building in o he
design phase.
2
2.
.
Residen ial Building: Case S udy
In e ms o ypology, he building is a symme ical U-shaped block i e s o ies high, wi h housing
uni s, an in e io cou ya d, a sou heas - acing main açade, a g ound loo de o ed o comme cial
p emises, and an unde g ound ca pa k (Figu e 1).
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Figu e 1. Floo plan.
Table 1. Cha ac e iza ion o he he mal en elope in i s o iginal condi ion and a e e o i ing.
Building elemen
U (W/m² K)
Re o i imp o emen
O iginal
Re o i ing
Façades
24 cm po ous ce amic b ick wi h ex e io
ende ing and in e io plas e ing
0.94 0.33 Ven ila ed açade wi h 6 cm
MW
S ai case: single laye , pe o a ed b ick wall, 5
cm MW insula ion, ai chambe exceeding 5 cm,
plas e ed hollow b ick wall.
0.52 0.52
Openings Anodized aluminum ames wi h 5 mm single
glazing.
5.70
3.8
4 + 6 + 6 glass
3.3
Low emission 4 + 6 + 6 glass
Roo s
Ce amic iles, key mo a , b ick boa d bedded on
sand, asphal shee , le eling mo a , slopes
o med wi h 10 cm cellula conc e e and 5 cm
XPS on amewo k.
0.47 0.47
Floo s Unidi ec ional amewo k 25 + 5 semi- esis an
jois s inished wi h e azzo loo ing and plas e .
2.25 0.54 5 cm XPS insula ion, ai
chambe and me al alse ceiling.
Table 1 shows low le els o he mal insula ion in he he mal en elope, pa icula ly on açades and
ex e nal amewo ks, and in he aluminum doo s and windows wi h single glazing. The mog aphic
analysis shows he mal de iciency, e ealing conside able ene gy dissipa ion in he building en elope
h ough he mally weake elemen s, wi h he mal b idges in amewo k edges, pilla s, and
window ames.
The no h- and eas - acing açades o he building a e ba ely in con ac wi h he sun in he win e ,
bu he sou heas and sou hwes açades a e exposed o i , a p oblem which is esol ed in summe wi h
awning sys ems a some poin s.
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The main s a egies in he e o i p oposal o win e and summe a e:
- Encou agemen o ai low, mainly h ough na u al en ila ion a nigh du ing he summe
depending on ex e io condi ions.
- Ene gy conse a ion, imp o ing insula ion, and he accumula ion o ene gy h ough he mal ine ia.
To gua an ee comple e e iciency in he summe ime he he mal mass mus be in con ac wi h he
nigh ai low o ensu e passi e cooling, while in win e he wall mus ecei e sola adia ion.
- Sola Radia ion and Sola Con ol, cap u ing sola adia ion in win e and ensu ing sui able
p o ec ion om adia ion in summe (sola p o ec ion o he openings wi h he mos sola exposu e,
depending on o ien a ion, using sliding, olding, o ixed sla sys ems. Eas and wes windows a e
p o ec ed by ex e nal mo able shading de ices which a e ac i a ed du ing he cooling pe iod).
- The mal en elope insula ion (Table 1) using a en ila ed açade sys em, wi h a ce amic o me al
inish. This sys em educes he mal b idges in beams and pilla s and along he join s be ween b icks
and load-bea ing s uc u e.
- The mal ansmi ance o windows, inco po a ing double glazing and imp o ing insula ion on
ex e nal amewo k (Figu e 2).
Figu e 2. Building in o iginal condi ion (le ) and ollowing e o i ( igh ).
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3
3.
.
Analysis Me hodology
The ene gy assessmen o he building, bo h o i s o iginal condi ion and o he e o i p ojec ,
de ined he in e en ion s a egy. The compu e p og am used was Design Builde e sion 2.2.5.004,
whose simula ion engine, Ene gy Plus, enabled he au ho s o ob ain p ecise da a on annual, mon hly,
and hou ly demands o each model, as well as indoo empe a u e alues in housing uni s conside ed
o be ee unning. A compa a i e analysis was es ablished o measu e he p edic ed imp o emen
ollowing he ac ion.
Table 2. Ope a ing condi ions o he housing uni s.
Pe iod (h)
1-7
8-15
16
17-18
19
20-23
24
Summe empe a u e se ing (°C)
27
25
25
25
25
25
27
Win e empe a u e se ing (°C)
17
20
20
20
20
20
17
Sensi i e hea due o occupan s (W/m2)
Weekday
2.15
0.54
1,08
1.08
1.08
1.08
2.15
Weekend
2.15 2.15 2,15 2.15 2.15 2.15 2.15
La en hea due o occupan s (W/m2)
Weekday
1.36
0.34
0,68
0.68
0.68
0.68
1.36
Weekend
1.36 1.36 1,36 1.36 1.36 1.36 1.36
Ligh ing load (W/m2)
0.44
1.32
1,32
1.32
2.2
4.4
2.2
Appliance load (W/m2)
0.44
1.32
1,32
1.32
2.2
4.4
2.2
Figu e 3. De ails o building.
Ini ially, condi ions o occupancy ope a ions, ligh ing and appliance loads, and empe a u e
se ings (Table 2) we e es ablished. The occupancy schedule conside ed a ies depending on whe he
he day in ques ion is a weekday o weekend. Summe en ila ion a nigh was es ablished a ou ai
changes pe hou . In il a ions we e measu ed onsi e, using he Blowe Doo an p essu iza ion
me hod, wi h M2 p o ocol [15]. The g ills o openings h ough which ai was ex ac ed, mainly in
ki chens and ba h ooms, we e sealed. This was conside ed he mos sui able p o ocol o e alua ing he
ela ionship be ween he ai igh ness o housing uni s and hei ene gy demand, calcula ing 0.55 ai
changes pe hou in o iginal condi ion. Following e o i , and a e insula ing he ecesses and lin els
o he openings and imp o ing he ai igh ness o he window ame join s, his dec eased o 0.46 ai
changes pe hou .

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Summe egime was de ined as he pe iod be ween he mon hs o Ap il and Sep embe , and he es
o he yea was conside ed win e . Gi en he impo ance o he o ien a ion and posi ion o he
building, each o he 10 di e en housing uni ypes, which ook hei espec i e o ien a ions in o
accoun , was analyzed (Figu e 3). In addi ion an analysis o he a e age o all he op-s o y housing
uni s was conside ed.
4
4.
.
Ene gy Pe o mance o he Building
The ini ial diagnosis de ec ed de icien indoo com o condi ions a ec ing use s. A se ies o
calcula ions we e ca ied ou o es ablish he le els o he mal com o inside he housing uni s o
p o ide an in-dep h analysis o he mal habi abili y upg ades in he p oposal o ene gy e o i . These
calcula ions ollowed he ee unning hypo hesis and e alua ed he en i onmen al indica o s
o empe a u e and he mal oscilla ion by s udying local clima e, he mal e olu ion, and
ene gy cha ac e iza ion.
4.1. Loca ion and Clima e
The building is loca ed in he ci y o Co doba in he sou h o Spain (al i ude: 90 m, la i ude: 37° 50'
39'' N–longi ude: 4° 50' 46'' O).
The clima e is sub-con inen al Medi e anean wi h wa m summe s, e y high empe a u es
(maximum a e age empe a u es o 36 °C) and an a e age o o e 300 hou s o sun pe mon h om
June o Sep embe . The win e s a e mild and las om No embe o Ma ch, wi h sho sp ings and
au umns. Win e is he season wi h he mos ainy days, al hough he annual ain all le el is low.
Typical days we e calcula ed o he wo main annual pe iods as pa o he clima e analysis o he
loca ion, win e (Oc obe 1–Ma ch 31) and summe (Ap il 1–Sep embe 30). Janua y 15 and Augus
19 we e se as ep esen a i e days in e ms o he ou doo empe a u e alues o win e and
o summe .
Table 3. Clima e alues in Co doba. Pe iod: 1971–2000.
Jan
Feb
Ma
Ap
May
Jun
Jul
Aug
Sep
Oc
No
Dec
To al
A e age mon hly/annual empe a u e (°C)
9.2
10.9
13.5
15.4
19
23.5
27.2
27.2
24.0
18.5
13.2
10.2
17.6
A e age mon hly/annual maximum day
empe a u e (°C)
14.7 16.9 20.5 22.1 26.2 31.6 36.2 35.9 31.7 25.0 18.9 15.3 24.6
A e age mon hly/annual minimum day
empe a u e (°C)
3.7 4.9 6.4 8.6 11.8 15.5 18.1 18.5 16.2 12.1 7.6 5.2 10.7
A e age mon hly/annual ain all (mm)
64
53
40
61
34
17
3
3
24
62
85
89
536
A e age ela i e humidi y (%)
77
73
64
62
58
52
44
46
53
65
75
80
62
A e age mon hly/annual numbe o days
wi h ain all
≥
1 mm
7 6 5 8 5 2 1 1 2 6 6 8 56
A e age mon hly/annual hou s o sunshine
168
172
212
212
272
312
352
328
241
208
176
148
2800
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4.2. The mal E olu ion
Fo he s udy o he he mal e olu ion o he housing uni s he au ho s used he p ocedu e ollowed
by He as e al. [16], which moni o ed se e al buildings calcula ing indoo empe a u es in win e and
summe , and also analyzed he le el o he mal com o eached in each pe iod, comple ing he s udy
wi h he analysis o ypical days.
The a e age indoo empe a u es we e compa ed wi h he a e age ex e nal empe a u es, bo h
mon hly and on he ypical days, in o de o es ablish he he mal beha io o he housing uni s and
hei le el o com o . In he p oposal o e o i ing, he mon hly assessmen (Figu e 4) shows an
inc ease o abou 2 o 2.5 °C o he lowe empe a u es wi hin housing uni s in win e , while in he
summe he e is a educ ion o app oxima ely 1.5 o 2.5 °C o he highe empe a u es. The di e ences
in empe a u e o he di e en ypes and o ien a ions o housing uni s o bo h pe iods
become homogenized.
Figu e 4. A e age indoo empe a u e s. a e age ou doo empe a u e. O iginal condi ion
and ollowing e o i .
O iginal condi ion Re o i ing Ou doo empe a u e
The he mal e olu ion o he di e en ypes o housing uni h oughou he 24 hou s o he day was
analyzed o es ablish a wha poin s peak empe a u es occu . The ypical days o each season we e
analyzed, and cooling wi h a he mal oscilla ion anging be ween 12.5 and 21.5 °C was obse ed
be ween 15:00 and 20:00 hou s in some o he housing uni s in hei o iginal condi ion. A e
e o i ing all he housing uni s e ained a highe hea in ela ion o he ou doo empe a u e, hus
aising he lowe ange o empe a u es om 12.5 o 15.5 °C, wi h ela i ely s able beha io du ing he
day, lowe he mal oscilla ion be ween housing uni s, and e y homogeneous empe a u es (Figu e 5).
In summe , cooling occu s be ween 15:00 and 21:00 hou s and is mo e p onounced in he e o i
p ojec , along wi h a d op in oscilla ion om 30–35 °C o 28–33.5 °C. These alues a e high, due
mainly o he high ou doo empe a u e alues (Figu e 6).
The s udy o he mal ine ia h ough an ene gy balance be ween indoo and ou doo empe a u es
h oughou he 24 hou s o he day allows us o es ablish whe he o no o e hea ing occu s and i so,
when his akes place.
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Figu e 5. E olu ion o a e age indoo empe a u e on a ypical win e day. O iginal
condi ion (le ) and ollowing e o i ( igh ).
Housing Types Ou doo empe a u e
Figu e 6. E olu ion o a e age indoo empe a u e on a ypical summe day. O iginal
condi ion (le ) and ollowing e o i ( igh ).
Housing Types Ou doo empe a u e
In win e , in he e o i p oposal he inside o he housing uni s main ains a highe empe a u e
hanks o na u al hea ing. Ea ly in he mo ning, when he sun begins o hea he building, he
di e ence be ween ou doo and indoo empe a u es dec eases, peaking no iceably du ing ea ly
a e noon. This di e ence is caused by he inc ease in ou doo empe a u e, so he e is no de imen o
he indoo com o condi ions o he housing uni s (Figu e 7).
In summe he pe o mance o all he housing uni s ollows he same pa e n (Figu e 8), bu
imp o es a e e o i ing, wi h an inc ease in he mal oscilla ion compa ed o win e and a he mal
wa e wi h wo dis inc pe iods:
- A pe iod o lowe indoo empe a u e in which he ou doo empe a u es a e mo e han 5 °C highe
han indoo ones. This phenomenon occu s be ween 15:00 and 22:00 hou s, and is desi able in a
summe wi h high sola adia ion, since i a oids o e hea ing and imp o es he mal com o .
- A pe iod o highe indoo empe a u e in which he di e ence be ween indoo and ou doo
empe a u es can each 10 °C in he ea ly s ages o he day when he ou doo empe a u e is no oo
high and he housing uni s a e s ill making use o he hea accumula ed he p e ious day.
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Figu e 7. S udy o he mal ine ia in he win e . O iginal condi ion and ollowing e o i .
Figu e 8. S udy o he mal ine ia in he summe . O iginal condi ion (le ) and ollowing
e o i ( igh ).
4.3. Ene gy Cha ac e iza ion
To es ablish he he mal p ocess occu ing in buildings, compa isons a e p esen ed be ween indoo
and ou doo empe a u es, ha is o say, e ec i e hea ing o cooling, a he han oom empe a u e. A
apid assessmen o he le el o he mal com o can be ob ained by compa ing his wi h an indoo
com o band.
Es ablishing indoo com o bands is simply a guide o he mal com o . The concep o he mal
com o is a he subjec i e and di icul o e alua e. A com o empe a u e in e al o be ween
20–22 °C in win e and 22–27 °C in summe was es ablished. This ollowed he heo e ical s udies by
Fange [17], inco po a ed in o no m UNE EN ISO 7730:2006; he adap i e models o Auliciems and
Szokolay [18], which include ex e nal clima e condi ions; and Gi oni’s climog aph [19], which is
pa icula ly sui ed o wa m d y clima es.