The authors discuss this longhouse with surrounding structures, which were pits of some sort, and they invite further research to see if these differing structures were contemporary. I believe the question of similar, richly-filled pits is gaining attention elsewhere, if I understand correctly (more below).
The authors here question the notion that these surrounding pits were for refuse or burial, even though the material is conglomerated, silty garbage-looking stuff, like orphan pottery fragments. I believe this might be similar to a subject Blanco-Gonzales tackled in a paper earlier in 2014 [here], concerning the Central Meseta. This again being what looked like burial cairns or trash pits, but for one, lack a body and two appear to have been re-used. I speculated then that these might be silages, since winter haying does not appear to have existed before medieval times.
The issue of orphan pottery fragments in silages is something I speculated on [here], being that the farmer may have used pulverized pottery as supplements, which sounds crazy but has a practical value. (Modern cattle are given licks. Still they will eat rocks, presumably for minerals) Whatever this main building was (i.e. tavern, house), it certainly had livestock there as well.
As a side note, I posted a study discussing the provenance of some of earlier bell beaker pottery near this area in Arlanzón [here]. This was done using chemical analysis and the authors concluded that some of the Bell Beaker pottery appears to have come from a potterhouse on the Guadiana in Southern Portugal or Spain.
MARTÍN, LUIS VILLANUEVA, EDUARDO CARMONA BALLESTERO, MIGUEL ÁNGEL ARNAIZ ALONSO, and MARÍA EUGENIA DELGADO ARCEO. "La articulación del espacio en el “campo de hoyos” de Manantial de Peñuelas (Celada del Camino, Burgos)." June, 2014 [Link]