Je pense que l'on peut garder le terme de section ici. C'est un terme aussi bien général que spécifique utilisé dans de nombreux domaines.

Voici quelques exemples de définition de "section" dans le domaine de la construction, du bâtiment, de l'architecture (cf. en-tête "Works for public market")
"Section

DESSIN. Représentation graphique sous forme de coupe transversale ou longitudinale, d'un ensemble complexe (édifice, machine, navire, véhicule). La section est située, sur les autres vues correspondantes, par un axe et sur le plan sécant lui-même, par des hachures (Bég.Dessin1978).

Section plane. Courbe ou surface produite par l'intersection d'un solide et d'un plan. Une section plane est produite par un plan de surface ou de volume (Bég.Dessin1978)."

https://www.cnrtl.fr/lexicographie/section

"Section d'un bâtiment, le profil ou la délinéation qui se fait des hauteurs et des profondeurs élevées sur le plan, comme si l'on coupait le bâtiment pour voir l'intérieur."

http://dictionnaire.sensagent.leparisien.fr/section/fr-fr/

Voici un extrait d'un site qui peut éclairer la question (cf. "completion date" and "section")

"Where the contract requires sectional completion of the works, then separate dates for completion and separate rates of liquidated and ascertained damages should be set for each section.

NB: There can be a cascade effect, where delays in one section cause delays in another. The contractor may then be liable to pay liquidated and ascertained damages for each section.

https://www.designingbuildings.co.uk/wiki/Completion_date_in...

This is the term I most often encounter in FR project contracts of this sort, to describe the individual 'work packages' making up the whole. Do note that they do also often use it in this rather curious way, to suggest that a 'work package' can actually do something, as if it were an actual entity; I suppos to an extent the term is used as shorthand for '(the contractor responsible for) work package'.

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Note added at 6 hrs (2020-06-17 14:12:12 GMT)
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Some people seem to have missed the admittedly scant clues in the context we do have.

The mention of 'works', 'Taking-over', and 'Particular conditions' all hint at a works contract...

And non déplaise à Germaine, in FR-FR, certainly, 'un lot' very often does refer not only to a 'work package' (e.g. Électricité courants faibles), but also to the Contractor who wins the bid for this particular 'lot' — typically, things like 'le lot Gros-œuvre est responsible de l'exécution des réservations et/ou perçages selon les plans à fournir par le lot Assainissement'.

This is why I queried the EN in this source text, since the various mentions sound slightly out of place in 'normal' EN. The 'Particular Conditions' smacks very much of FR 'CCTP', and it it is not uncommon to talk about the work under the Contract as a whole and subdivided into 'Lots' — we do even sometimes call them 'lots' in EN too, though I confess 'section' is a new one on me!

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Note added at 7 hrs (2020-06-17 15:52:04 GMT)
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In the light of that vital extra context, I would now have given it a C/L of 5 — this is exactly the term I have seen used in the very many FR documents of this type I have translated in connection with éoliens