Across:
1 Psychologist dismisses pigsty (‘psychologist’ dismisses ‘pigsty’ = scholo = SCHOOL) or is that the teacher’s place? (SCHOOL),
4 Engrossed (ABSORBED) by new (= anagram indicator) bars (bars = ABS-R-) around Ring (-O-) with nightspot (-BED) (ABSORBED),
9 Dorm in (dorm in = NIMROD) retrospect (r= reversal indicator) is for one of those in Genesis (in the Bible, Nimrod, the great-grandson of Noah, known for his skill as a hunter = NIMROD),
10 Archaeologist’s achievements (FIND-S) include interpreting neoclassical gold heads (‘interpreting neoclassical gold’ heads = -ING) (FINDINGS) – the ones the researchers came up with (FINDINGS),
12 There’s no rush (UNHURRIED) offering introductions to universal novel (introductions to ‘universal novel’ = UN-) by Swift (swift = -HURRIED) (UNHURRIED),
13 Portly type (OBESE) honours royal subject (Officer of the Most Excellent Order of the British Empire = OBE-) at point-to-point (south + east = S+E = -SE) (OBESE),
14 Opens 18 across (opens ‘self-employed’ = SELF -) to give it to 7 down (give - INTEREST to ‘banker’) (SELF-INTEREST) out of lack of consideration for others (SELF-INTEREST),
18 Has a job going it alone (SELF-EMPLOYED) in Labour – for one, not being part of the general staff (SELF-EMPLOYED),
21 Bit of The Paper illustrating (bit of The ‘Paper illustrating’ = PERIL) danger (PERIL),
22 Return the compliment (RETALIATE) in a literate (a literate = RETALIATE) novel (= anagram indicator),
24 Who’s labouring on the job (EMPLOYED) to commission (EMPLOY-) writer? (-ED) (EMPLOYED),
25 Wax lyrically about (PRAISE) Persia (Persia = PRAISE) on the rampage (= anagram indicator),
26 Out of juice (DEAD) with money for jam (EASY) (DEAD EASY) and a piece of cake (DEAD EASY),
27 Included in Vespa personalised (included in ‘Vespa personalised’ = PAPERS) for archivist going to work (PAPERS).
Down:
1 Paper (SUN-) goes bankrupt (bust = -BU-ST) over writing (from the 3Rs = -R-) (SUNBURST) emerging luminously from The Cloud (emerging luminously from the cloud = SUNBURST),
2 Produced by one of those at the start of 5 down (one of the ‘builders’ produced HOME) to aid (HELP) (HOME HELP) social worker (HOME HELP),
3 Dudley Moore releases medley (‘Dudley Moore’ releases ‘medley’ = duoor = ODOUR) with an unpleasant air (ODOUR),
5 Homemaker’s (BUILDERS) partner (MATE) (BUILDERS MATE) is learning a trade on site (BUILDERS MATE),
6 Brave (bold) heading off (b) (‘bold’ without ‘b’ = OLD) by ship (-SS-) consumed by scotch (scotch/foil = FO-IL) (OLD FOSSIL) – the type that has matured without exposure for a long, long time (OLD FOSSIL),
7 Heartbroken without other (‘heartbroken’ without ‘other’ = earbkn = BANKER) person holding the capital (BANKER),
8 That’s a handy one for the board (white/blackboard = DUSTER) in clean (DUST-) hospital ward (-ER) (DUSTER),
11 Students (SIXTH-FORMERS) of Beethoven’s Pastoral Symphony (Beethoven’s SIXTH-) from awful (= anagram indicator) Reform (FORMER-) School (-S) (SIXTH-FORMERS),
15 Perfect place (IDEAL HOME) for one (I-) trade (-DEAL) and a fair amount of (half of) 2 down (half of ‘home help’ = HOME) (IDEAL HOME),
16 Somewhere for the builders (S-ITE) going around at the end of the day (end of ‘day’ = -Y-) for drinks (-BAR-) (SYBARITE) in The Epicure (SYBARITE),
17 It’s nothing to do (IDLENESS) with crushing (= anagram indicator) linseeds (linseeds = IDLENESS),
19 Span (SPREAD) of sun coming out of underpass (‘sun’ coming out of ‘underpass’ = derpas = SPREAD),
20 Foreign spirit (GRAPPA) doctor (G-P-) outside Knock (knock = -RAP-) is anonymous (-A) (GRAPPA),
23 Sample of popular variety (sample of ‘popular variety’ = LARVA) for grub (LARVA).