Across:
1 Some characters layoff a bricklayer (some characters “layoff a bricklayer” = FABRIC) in construction, in the building sense (FABRIC),
4 Incidents (EPISODES) of nasty (= anagram indicator) spies (spies = EPIS-S) hiding most of (c) the code (“code” without “c” = -ODE-) (EPISODES),
9 Ring (O-) Lima (-L-) out of desire (desire/wish = -W-ISH) (OWLISH) for wise-looking type (OWLISH),
10 Maids lie (maids lie = IDEALISM) badly (= anagram indicator) out of unrealistic pursuit of perfection (IDEALISM),
12 Pulitzer (Pulitzer PRIZE) for Wall Street optimist (stock market buyer = BULL) (PRIZE BULL) – the best for anyone with stock issues (PRIZE BULL),
13 It’s a measure of the capacity (LITRE) covered up by Botticelli treatment (covered up by “Botticelli treatment” = LITRE),
14 Knows the value of going from one capital to another (MONEY CHANGER) by working out how much reportedly (= homophone indicator) Frank’s (“franks” = “francs”) conversion costs MONEY CHANGER),
18 Is this still (still in the picture sense = TRANSPARENCY) expected to give one clarity? (TRANSPARENCY),
21 Born (B-) with the burden of responsibility (-ONUS) (BONUS) to Commission (BONUS),
22 The art of the perfect delivery? (ELOCUTION) That’ll teach you in a manner of speaking! (ELOCUTION),
24 Gloria in (Gloria in = ORIGINAL) dress? (= anagram indicator) That’s a first! (ORIGINAL),
25 Local fans (FIENDS for One Direction (east = -E-) in spots (finds = FI-NDS) (FIENDS),
26 Bar (BLOCKADE) musical type (rock music) losing the head (r) (“rock” without “r” = -OCK-) consumed by a bit of grass (BL-ADE of grass) (BLOCKADE),
27 A yard (-Y-) from park (-P-) in low pitch (B-ASS) (BYPASS) does one’s heart good (heart BYPASS).
Down:
1 Measurement (FOOT) relating to milk in the forceful sense (PUMP) (FOOT PUMP) is responsible for inflation in 5 down perhaps (FOOT PUMP is responsible for inflation in “paddling pool”),
2 Basel gin (Basel gin = BELGIANS) produced (= anagram indicator) for those around European HQ (BELGIANS around EU HQ in Brussels),
3 Put out (ISSUE) by what the parents produced (ISSUE),
5 Is this where younger generation learn stroke (PADDLING POOL) politics? Initially (“politics” initially = P-), it’s confusing (-ADDLING) to put together! (POOL), (PADDLING POOL),
6 In comparison, it’s not worth much (considered unimportant = SMALL BEER) to ask the barman for it (SMALL BEER),
7 Gets side-tracked (DRIFTS) by Poles coming off field sports (“Poles” coming off “field sports” = fidsrt = DRIFTS),
8 Seethe (SIMMER) with one of the cards (SIM- card) off nice beach (off Nice, French beach = “sea” = -MER),
11 A good deal (MUCH) that’s popular (IN) to order (DEMAND) in Vogue (MUCH IN DEMAND),
15 Measure (YARDSTICK) out the back (YARD-) post (-STICK) (YARDSTICK),
16 One (I-) barber’s pole (-SIGN-) in Ulster (-N-I-) is a (-A) (INSIGNIA) badge of honour (INSIGNIA),
17 Down under (HYPNOSIS) – that brings me back to my childhood (HYPNOSIS),
19 Dean leaves broad beans (“Dean” leaves “broad beans” = broabs = ABSORB) to soak (ABSORB),
20 One (I-) doing (doing = -NDIGO) redevelopment (= anagram indicator) (INDIGO) for Violet (INDIGO),
23 Scotland is not part of dysfunctional (“Scotland” is not part of “dysfunctional” = yfuni = UNIFY) link-up (UNIFY).